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Dynamic Characteristics of Functionally Graded Timoshenko Beams by Improved Differential Quadrature Method
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作者 Xiaojun Huang Liaojun Zhang +1 位作者 Hanbo Cui Gaoxing Hu 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第8期1647-1668,共22页
This study proposes an effective method to enhance the accuracy of the Differential Quadrature Method(DQM)for calculating the dynamic characteristics of functionally graded beams by improving the form of discrete node... This study proposes an effective method to enhance the accuracy of the Differential Quadrature Method(DQM)for calculating the dynamic characteristics of functionally graded beams by improving the form of discrete node distribution.Firstly,based on the first-order shear deformation theory,the governing equation of free vibration of a functionally graded beam is transformed into the eigenvalue problem of ordinary differential equations with respect to beam axial displacement,transverse displacement,and cross-sectional rotation angle by considering the effects of shear deformation and rotational inertia of the beam cross-section.Then,ignoring the shear deformation of the beam section and only considering the effect of the rotational inertia of the section,the governing equation of the beam is transformed into the eigenvalue problem of ordinary differential equations with respect to beam transverse displacement.Based on the differential quadrature method theory,the eigenvalue problem of ordinary differential equations is transformed into the eigenvalue problem of standard generalized algebraic equations.Finally,the first several natural frequencies of the beam can be calculated.The feasibility and accuracy of the improved DQM are verified using the finite element method(FEM)and combined with the results of relevant literature. 展开更多
关键词 Timoshenko beams functionally graded materials dynamic characteristics natural frequency improved differential quadrature method
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A Hybrid Level Set Optimization Design Method of Functionally Graded Cellular Structures Considering Connectivity
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作者 Yan Dong Kang Zhao +1 位作者 Liang Gao Hao Li 《Computers, Materials & Continua》 SCIE EI 2024年第4期1-18,共18页
With the continuous advancement in topology optimization and additive manufacturing(AM)technology,the capability to fabricate functionally graded materials and intricate cellular structures with spatially varying micr... With the continuous advancement in topology optimization and additive manufacturing(AM)technology,the capability to fabricate functionally graded materials and intricate cellular structures with spatially varying microstructures has grown significantly.However,a critical challenge is encountered in the design of these structures–the absence of robust interface connections between adjacent microstructures,potentially resulting in diminished efficiency or macroscopic failure.A Hybrid Level Set Method(HLSM)is proposed,specifically designed to enhance connectivity among non-uniform microstructures,contributing to the design of functionally graded cellular structures.The HLSM introduces a pioneering algorithm for effectively blending heterogeneous microstructure interfaces.Initially,an interpolation algorithm is presented to construct transition microstructures seamlessly connected on both sides.Subsequently,the algorithm enables the morphing of non-uniform unit cells to seamlessly adapt to interconnected adjacent microstructures.The method,seamlessly integrated into a multi-scale topology optimization framework using the level set method,exhibits its efficacy through numerical examples,showcasing its prowess in optimizing 2D and 3D functionally graded materials(FGM)and multi-scale topology optimization.In essence,the pressing issue of interface connections in complex structure design is not only addressed but also a robust methodology is introduced,substantiated by numerical evidence,advancing optimization capabilities in the realm of functionally graded materials and cellular structures. 展开更多
关键词 Hybrid level set method functionally graded cellular structure CONNECTIVITY interpolated transition optimization design
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Transfer matrix method for free and forced vibrations of multi-level functionally graded material stepped beams with different boundary conditions
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作者 Xiaoyang SU Tong HU +3 位作者 Wei ZHANG Houjun KANG Yunyue CONG Quan YUAN 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2024年第6期983-1000,共18页
Functionally graded materials(FGMs)are a novel class of composite materials that have attracted significant attention in the field of engineering due to their unique mechanical properties.This study aims to explore th... Functionally graded materials(FGMs)are a novel class of composite materials that have attracted significant attention in the field of engineering due to their unique mechanical properties.This study aims to explore the dynamic behaviors of an FGM stepped beam with different boundary conditions based on an efficient solving method.Under the assumptions of the Euler-Bernoulli beam theory,the governing differential equations of an individual FGM beam are derived with Hamilton’s principle and decoupled via the separation-of-variable approach.Then,the free and forced vibrations of the FGM stepped beam are solved with the transfer matrix method(TMM).Two models,i.e.,a three-level FGM stepped beam and a five-level FGM stepped beam,are considered,and their natural frequencies and mode shapes are presented.To demonstrate the validity of the method in this paper,the simulation results by ABAQUS are also given.On this basis,the detailed parametric analyses on the frequencies and dynamic responses of the three-level FGM stepped beam are carried out.The results show the accuracy and efficiency of the TMM. 展开更多
关键词 transfer matrix method(TMM) free vibration forced vibration functionally graded material(FGM) stepped beam
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Application of NSR-AISC Method in Reserve Estimation and Technical Economic Evaluation of Low-Grade Polymetallic Deposits: Taking a Low-Grade Copper-Molybdenum Mine in Guangdong Province as an Example
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作者 Yao Xue Tengfei Li 《World Journal of Engineering and Technology》 2024年第3期731-741,共11页
The development and utilization of low-grade polymetallic deposits with strategic mineral resources is one of the important measures to alleviate the current high dependence on strategic mineral resources in China. Ho... The development and utilization of low-grade polymetallic deposits with strategic mineral resources is one of the important measures to alleviate the current high dependence on strategic mineral resources in China. However, domestic mining enterprises and most mining consulting and design institutes usually use general industrial indicators to carry out reserve estimation and technical and economic feasibility studies on low-grade polymetallic deposits, which cannot truly reflect the economic value of such deposits. The article expounds on the definitions of net return value (NSR) and on-site total maintenance cost (AISC) of common ore smelters in the evaluation of overseas mineral resources. Taking a low-grade polymetallic copper-molybdenum mine in Guangdong Province as an example, comparing the research results showed the NSR-AISC method and the general industrial index method in low-grade polymetallic deposit. There are huge differences in the results of reserve estimation;through the further introduction of Taylor’s formula and the research results on the relationship between investment intensity and production scale, a more reasonable mine life and investment scale are recommended, and a more in-depth comparative study has been carried out in the dimension of technical and economic indicators. Based on the comparative study of the above two methods in reserve estimation and the evaluation results of technical and economic indicators, the author believes that the NSR-AISC method can better reflect the true value of low-grade polymetallic ore projects, and should be popularized and applied in resource evaluation and development practice. This article further describes the application status of the NSR-AISC method for reserve estimation and the evaluation of technical economic indicators, and suggests the main points that should be paid attention to in the use of the NSR-AISC method. 展开更多
关键词 NSR-AISC method General Industrial Indicators Low-Grade Polymetallic Ore
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Parametric resonance of axially functionally graded pipes conveying pulsating fluid
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作者 Jie JING Xiaoye MAO +1 位作者 Hu DING Liqun CHEN 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2024年第2期239-260,共22页
Based on the generalized Hamilton's principle,the nonlinear governing equation of an axially functionally graded(AFG)pipe is established.The non-trivial equilibrium configuration is superposed by the modal functio... Based on the generalized Hamilton's principle,the nonlinear governing equation of an axially functionally graded(AFG)pipe is established.The non-trivial equilibrium configuration is superposed by the modal functions of a simply supported beam.Via the direct multi-scale method,the response and stability boundary to the pulsating fluid velocity are solved analytically and verified by the differential quadrature element method(DQEM).The influence of Young's modulus gradient on the parametric resonance is investigated in the subcritical and supercritical regions.In general,the pipe in the supercritical region is more sensitive to the pulsating excitation.The nonlinearity changes from hard to soft,and the non-trivial equilibrium configuration introduces more frequency components to the vibration.Besides,the increasing Young's modulus gradient improves the critical pulsating flow velocity of the parametric resonance,and further enhances the stability of the system.In addition,when the temperature increases along the axial direction,reducing the gradient parameter can enhance the response asymmetry.This work further complements the theoretical analysis of pipes conveying pulsating fluid. 展开更多
关键词 pipe conveying fluid axially functionally graded supercritical resonance multi-scale method parametric resonance
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Exact solution for thermal vibration of multi-directional functionally graded porous plates submerged in fluid medium
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作者 Quoc-Hoa Pham Van Ke Tran Phu-Cuong Nguyen 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第5期77-99,共23页
An analytical method for analyzing the thermal vibration of multi-directional functionally graded porous rectangular plates in fluid media with novel porosity patterns is developed in this study.Mechanical properties ... An analytical method for analyzing the thermal vibration of multi-directional functionally graded porous rectangular plates in fluid media with novel porosity patterns is developed in this study.Mechanical properties of MFG porous plates change according to the length,width,and thickness directions for various materials and the porosity distribution which can be widely applied in many fields of engineering and defence technology.Especially,new porous rules that depend on spatial coordinates and grading indexes are proposed in the present work.Applying Hamilton's principle and the refined higher-order shear deformation plate theory,the governing equation of motion of an MFG porous rectangular plate in a fluid medium(the fluid-plate system)is obtained.The fluid velocity potential is derived from the boundary conditions of the fluid-plate system and is used to compute the extra mass.The GalerkinVlasov solution is used to solve and give natural frequencies of MFG porous plates with various boundary conditions in a fluid medium.The validity and reliability of the suggested method are confirmed by comparing numerical results of the present work with those from available works in the literature.The effects of different parameters on the thermal vibration response of MFG porous rectangular plates are studied in detail.These findings demonstrate that the behavior of the structure within a liquid medium differs significantly from that within a vacuum medium.Thereby,they offer appropriate operational approaches for the structure when employed in various mediums. 展开更多
关键词 Plate-fluid contact Galerkin Vlasov's method Multi-directional functionally graded plate Novel porosity Thermal vibration Refined higher-order shear deformation theory
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Free vibration and buckling analysis of polymeric composite beams reinforced by functionally graded bamboo fbers
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作者 H.M.FEIZABAD M.H.YAS 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2024年第3期543-562,共20页
Natural fibers have been extensively researched as reinforcement materials in polymers on account of their environmental and economic advantages in comparison with synthetic fibers in the recent years.Bamboo fibers ar... Natural fibers have been extensively researched as reinforcement materials in polymers on account of their environmental and economic advantages in comparison with synthetic fibers in the recent years.Bamboo fibers are renowned for their good mechanical properties,abundance,and short cycle growth.As beams are one of the fundamental structural components and are susceptible to mechanical loads in engineering applications,this paper performs a study on the free vibration and buckling responses of bamboo fiber reinforced composite(BFRC)beams on the elastic foundation.Three different functionally graded(FG)layouts and a uniform one are the considered distributions for unidirectional long bamboo fibers across the thickness.The elastic properties of the composite are determined with the law of mixture.Employing Hamilton’s principle,the governing equations of motion are obtained.The generalized differential quadrature method(GDQM)is then applied to the equations to obtain the results.The achieved outcomes exhibit that the natural frequency and buckling load values vary as the fiber volume fractions and distributions,elastic foundation stiffness values,and boundary conditions(BCs)and slenderness ratio of the beam change.Furthermore,a comparative study is conducted between the derived analysis outcomes for BFRC and homogenous polymer beams to examine the effectiveness of bamboo fibers as reinforcement materials,demonstrating the significant enhancements in both vibration and buckling responses,with the exception of natural frequencies for cantilever beams on the Pasternak foundation with the FG-◇fiber distribution.Eventually,the obtained analysis results of BFRC beams are also compared with those for carbon nanotube reinforced composite(CNTRC)beams found in the literature,indicating that the buckling loads and natural frequencies of BFRC beams are lower than those of CNTRC beams. 展开更多
关键词 bamboo fiber free vibration buckling analysis functionally graded(FG)beam elastic foundation generalized differential quadrature method(GDQM)
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Observation of Curative Effect of Surgical Nursing in Patients with Grade III Hand-Foot Syndrome
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作者 Liping Zhang Lijuan Zhang +6 位作者 Yun Ding Lili Han Jiamin Kuang Qinghua Luo Xinhua Xie Zeyu Shuang Qiaoling Zhong 《Journal of Cancer Therapy》 2024年第8期280-286,共7页
Objective: To investigate the effect of surgical nursing on grade III Hand-Foot Syndrome (HFS) induced by Doxorubicin hydrochloride liposome chemotherapy after breast cancer surgery. Method: From January 2019 to Decem... Objective: To investigate the effect of surgical nursing on grade III Hand-Foot Syndrome (HFS) induced by Doxorubicin hydrochloride liposome chemotherapy after breast cancer surgery. Method: From January 2019 to December 2019, 10 patients with HFS grade III caused by Doxorubicin hydrochloride liposome chemotherapy after breast cancer surgery in the Breast Department of Cancer Prevention and Treatment Center of Sun Yat-sen University were selected, and surgical nursing methods were used to intervene and observe the therapeutic effects of the patients. Results: One patient was cured within 7 days, the cure rate was 10% in 7 days, 8 patients were cured within 10 days, the cure rate was 80% in 10 days, 10 patients were cured within 15 days, the cure rate was 100% in 15 days. Conclusion: The surgical nursing method is effective for patients with grade III HFS caused by Doxorubicin hydrochloride liposome chemotherapy after breast cancer surgery, shortening the treatment time of HFS, and is worthy of clinical promotion. 展开更多
关键词 Surgical Nursing methods Breast Cancer CHEMOTHERAPY Grade III Hand-Foot Syndrome
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Free vibration of non-uniform axially functionally graded beams using the asymptotic development method 被引量:5
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作者 Dongxing CAO Yanhui GAO 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2019年第1期85-96,共12页
The asymptotic development method is applied to analyze the free vibration of non-uniform axially functionally graded(AFG) beams, of which the governing equations are differential equations with variable coefficients.... The asymptotic development method is applied to analyze the free vibration of non-uniform axially functionally graded(AFG) beams, of which the governing equations are differential equations with variable coefficients. By decomposing the variable flexural stiffness and mass per unit length into reference invariant and variant parts, the perturbation theory is introduced to obtain an approximate analytical formula of the natural frequencies of the non-uniform AFG beams with different boundary conditions.Furthermore, assuming polynomial distributions of Young's modulus and the mass density, the numerical results of the AFG beams with various taper ratios are obtained and compared with the published literature results. The discussion results illustrate that the proposed method yields an effective estimate of the first three order natural frequencies for the AFG tapered beams. However, the errors increase with the increase in the mode orders especially for the cases with variable heights. In brief, the asymptotic development method is verified to be simple and efficient to analytically study the free vibration of non-uniform AFG beams, and it could be used to analyze any tapered beams with an arbitrary varying cross width. 展开更多
关键词 AXIALLY functionally graded(AFG)beam NON-UNIFORM NATURAL frequency ASYMPTOTIC development method
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Geochemical and Geostatistical Studies for Estimating Gold Grade in Tarq Prospect Area by K-Means Clustering Method 被引量:7
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作者 Adel Shirazy Aref Shirazi +1 位作者 Mohammad Hossein Ferdossi Mansour Ziaii 《Open Journal of Geology》 2019年第6期306-326,共21页
Tarq geochemical 1:100,000 Sheet is located in Isfahan province which is investigated by Iran’s Geological and Explorations Organization using stream sediment analyzes. This area has stratigraphy of Precambrian to Qu... Tarq geochemical 1:100,000 Sheet is located in Isfahan province which is investigated by Iran’s Geological and Explorations Organization using stream sediment analyzes. This area has stratigraphy of Precambrian to Quaternary rocks and is located in the Central Iran zone. According to the presence of signs of gold mineralization in this area, it is necessary to identify important mineral areas in this area. Therefore, finding information is necessary about the relationship and monitoring the elements of gold, arsenic, and antimony relative to each other in this area to determine the extent of geochemical halos and to estimate the grade. Therefore, a well-known and useful K-means method is used for monitoring the elements in the present study, this is a clustering method based on minimizing the total Euclidean distances of each sample from the center of the classes which are assigned to them. In this research, the clustering quality function and the utility rate of the sample have been used in the desired cluster (S(i)) to determine the optimum number of clusters. Finally, with regard to the cluster centers and the results, the equations were used to predict the amount of the gold element based on four parameters of arsenic and antimony grade, length and width of sampling points. 展开更多
关键词 GOLD Tarq K-MEANS CLUSTERING method Estimation of the Elements GRADE K-MEANS
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Buckling analysis of functionally graded plates partially resting on elastic foundation using the differential quadrature element method 被引量:4
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作者 Arash Shahbaztabar Koosha Arteshyar 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2019年第1期174-189,I0005,共17页
We extend the differential quadrature element method (DQEM) to the buckling analysis of uniformly in-plane loaded functionally graded (FG) plates fully or partially resting on the Pasternak model of elastic support. M... We extend the differential quadrature element method (DQEM) to the buckling analysis of uniformly in-plane loaded functionally graded (FG) plates fully or partially resting on the Pasternak model of elastic support. Material properties of the FG plate are graded in the thickness direction and assumed to obey a power law distribution of the volume fraction of the constituents. To set up the global eigenvalue equation, the plate is divided into sub-domains or elements and the generalized differential quadrature procedure is applied to discretize the governing, boundary and compatibility equations. By assembling discrete equations at all nodal points, the weighting coefficient and force matrices are derived. To validate the accuracy of this method, the results are compared with those of the exact solution and the finite element method. At the end, the effects of different variables and local elastic support arrangements on the buckling load factor are investigated. 展开更多
关键词 Differential QUADRATURE element method Pasternak elastic support Critical BUCKLING load Functionally GRADED plates
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Large deformation analysis of a cantilever beam made of axially functionally graded material by homotopy analysis method 被引量:2
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作者 Xin LIN Yixin HUANG +1 位作者 Yang ZHAO Tianshu WANG 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2019年第10期1375-1386,共12页
Large deformation of a cantilever axially functionally graded (AFG) beam subject to a tip load is analytically studied using the homotopy analysis method (HAM). It is assumed that its Young’s modulus varies along the... Large deformation of a cantilever axially functionally graded (AFG) beam subject to a tip load is analytically studied using the homotopy analysis method (HAM). It is assumed that its Young’s modulus varies along the longitudinal direction according to a power law. Taking the solution of the corresponding homogeneous beam as the initial guess and obtaining a convergence region by adjusting an auxiliary parameter, the analytical expressions for large deformation of the AFG beam are provided. Results obtained by the HAM are compared with those obtained by the finite element method and those in the previous works to verify its validity. Good agreement is observed. A detailed parametric study is carried out. The results show that the axial material variation can greatly change the deformed configuration, which provides an approach to control and manage the deformation of beams. By tailoring the axial material distribution, a desired deformed configuration can be obtained for a specific load. The analytical solution presented herein can be a helpful tool for this procedure. 展开更多
关键词 large deformation BEAM AXIALLY functionally GRADED (AFG) material Euler-Bernoulli BEAM HOMOTOPY ANALYSIS method (HAM)
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Evaluation of umami taste components of mushroom (Suillus granulatus) of different grades prepared by different drying methods 被引量:7
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作者 Xiuhong Zhao Yunyun Wei +2 位作者 Xue Gong Heran Xu Guang Xin 《Food Science and Human Wellness》 SCIE 2020年第2期192-198,共7页
Suillus granulatus is a valuable wild edible mushroom with a strong umami taste.Different grades of S.granulatus were dried by different methods,including natural air drying(ND),hot air drying(HAD),vacuum drying(VD),a... Suillus granulatus is a valuable wild edible mushroom with a strong umami taste.Different grades of S.granulatus were dried by different methods,including natural air drying(ND),hot air drying(HAD),vacuum drying(VD),and freeze drying(FD).Results showed that VD samples of all grades had the highest equivalent umami concentration(EUC)value(P<0.05).The second grade of ND samples showed the highest EUC value(P<0.05).The first grade of HAD samples showed the highest EUC value(P<0.05).The third grade of FD samples showed the highest EUC value(P<0.05).The third grade of VD samples had a higher EUC value than the other grades of samples dried by VD.Electronic tongue results indicated no significant differences between samples of all grades dried by all methods.Thus,umami taste components are affected by drying method and grade.VD is an appropriate drying method for all sample grades.ND,HAD,and FD are suitable for second-,first-,and third-grade samples,respectively. 展开更多
关键词 Suillus granulatus drying methods GRADE umami taste components
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A novel method to predict static transmission error for spur gear pair based on accuracy grade 被引量:3
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作者 LIU Chang SHI Wan-kai +1 位作者 Francesca Maria CURÀ Andrea MURA 《Journal of Central South University》 SCIE EI CAS CSCD 2020年第11期3334-3349,共16页
This paper proposes a novel method to predict the spur gear pair’s static transmission error based on the accuracy grade,in which manufacturing errors(MEs),assembly errors(AEs),tooth deflections(TDs)and profile modif... This paper proposes a novel method to predict the spur gear pair’s static transmission error based on the accuracy grade,in which manufacturing errors(MEs),assembly errors(AEs),tooth deflections(TDs)and profile modifications(PMs)are considered.For the prediction,a discrete gear model for generating the error tooth profile based on the ISO accuracy grade is presented.Then,the gear model and a tooth deflection model for calculating the tooth compliance on gear meshing are coupled with the transmission error model to make the prediction by checking the interference status between gear and pinion.The prediction method is validated by comparison with the experimental results from the literature,and a set of cases are simulated to study the effects of MEs,AEs,TDs and PMs on the static transmission error.In addition,the time-varying backlash caused by both MEs and AEs,and the contact ratio under load conditions are also investigated.The results show that the novel method can effectively predict the range of the static transmission error under different accuracy grades.The prediction results can provide references for the selection of gear design parameters and the optimization of transmission performance in the design stage of gear systems. 展开更多
关键词 gear transmission error time-varying backlash prediction method accuracy grade
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Thermoelastic Analysis of Non-uniform Pressurized Functionally Graded Cylinder with Variable Thickness Using First Order Shear Deformation Theory(FSDT) and Perturbation Method 被引量:1
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作者 KHOSHGOFTAR M J MIRZAALI M J RAHIMI G H 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2015年第6期1149-1156,共8页
Recently application of functionally graded materials(FGMs) have attracted a great deal of interest. These materials are composed of various materials with different micro-structures which can vary spatially in FGMs... Recently application of functionally graded materials(FGMs) have attracted a great deal of interest. These materials are composed of various materials with different micro-structures which can vary spatially in FGMs. Such composites with varying thickness and non-uniform pressure can be used in the aerospace engineering. Therefore, analysis of such composite is of high importance in engineering problems. Thermoelastic analysis of functionally graded cylinder with variable thickness under non-uniform pressure is considered. First order shear deformation theory and total potential energy approach is applied to obtain the governing equations of non-homogeneous cylinder. Considering the inner and outer solutions, perturbation series are applied to solve the governing equations. Outer solution for out of boundaries and more sensitive variable in inner solution at the boundaries are considered. Combining of inner and outer solution for near and far points from boundaries leads to high accurate displacement field distribution. The main aim of this paper is to show the capability of matched asymptotic solution for different non-homogeneous cylinders with different shapes and different non-uniform pressures. The results can be used to design the optimum thickness of the cylinder and also some properties such as high temperature residence by applying non-homogeneous material. 展开更多
关键词 non-homogenous cylinder First order Shear Deformation Theory matched asymptotic method perturbation method functionally graded material
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Sound radiation of a functionally graded material cylindrical shell in water by mobility method 被引量:1
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作者 Buqing Xu,1,2, ) Shaopu Yang,3, and Haoyu Li1, 1)Department of Engineering Mechanics, Shijiazhuang Tiedao University, Shijiazhuang 050043, China 2)Provincial Laboratory of Traffic Safety and Control of Hebei, Shijiazhuang Tiedao University, Shijiazhuang 050043, China 3)Shijiazhuang Tiedao University, Shijiazhuang 050043, China 《Theoretical & Applied Mechanics Letters》 CAS 2011年第6期69-74,共6页
Based on the fundamental dynamic equations of functionally graded material (FGM) cylindrical shell, this paper investigates the sound radiation of vibrational FGM shell in water by mobility method. This model takes in... Based on the fundamental dynamic equations of functionally graded material (FGM) cylindrical shell, this paper investigates the sound radiation of vibrational FGM shell in water by mobility method. This model takes into account the exterior fluid loading due to the sound press radiated by the FGM shell. The FGM cylindrical shell was excited by a harmonic line radial force uniformly distributing along the generator. The FGM shell equations of motion, the Helmholtz equation in the exterior fluid medium and the continuity equation at fluid-shell interface are used in this vibroacoustic problem. The expressions of sound radiation efficiency and sound field of the FGM shell have been derived by mobility method. Radiation efficiency, modal mobility and the directivity pattern of the sound field are solved numerically. In particular, radiation efficiency and directivity pattern with various power law index are analyzed. 展开更多
关键词 fluid-loaded cylindrical shell functionally graded material mobility method sound radiation
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A Semi-analytical Method for Vibrational and Buckling Analysis of Functionally Graded Nanobeams Considering the Physical Neutral Axis Position 被引量:1
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作者 Farzad Ebrahimi Erfan Salari 《Computer Modeling in Engineering & Sciences》 SCIE EI 2015年第6期151-181,共31页
In this paper,a semi-analytical method is presented for free vibration and buckling analysis of functionally graded(FG)size-dependent nanobeams based on the physical neutral axis position.It is the first time that a s... In this paper,a semi-analytical method is presented for free vibration and buckling analysis of functionally graded(FG)size-dependent nanobeams based on the physical neutral axis position.It is the first time that a semi-analytical differential transform method(DTM)solution is developed for the FG nanobeams vibration and buckling analysis.Material properties of FG nanobeam are supposed to vary continuously along the thickness according to the power-law form.The physical neutral axis position for mentioned FG nanobeams is determined.The small scale effect is taken into consideration based on nonlocal elasticity theory of Eringen.The nonlocal equations of motion are derived through Hamilton’s principle and they are solved applying DTM.It is demonstrated that the DTM has high precision and computational efficiency in the vibration analysis of FG nanobeams.The good agreement between the results of this article and those available in literature validated the presented approach.The detailed mathematical derivations are presented and numerical investigations are performed while the emphasis is placed on investigating the effect of the several parameters such as neutral axis position,small scale effects,the material distribution profile,mode number,thickness ratio and boundary conditions on the normalized natural frequencies and dimensionless buckling load of the FG nanobeams in detail.It is explicitly shown that the vibration and buckling behaviour of a FG nanobeams is significantly influenced by these effects. 展开更多
关键词 Buckling Vibration Functionally GRADED nanobeam Neutral axis Differential transformation method NONLOCAL ELASTICITY
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Static and free vibration analyses of functionally graded porous variable-thickness plates using an edge-based smoothed finite element method 被引量:3
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作者 Trung Thanh Tran Quoc-Hoa Pham Trung Nguyen-Thoi 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2021年第3期971-986,共16页
The main purpose of this paper is to present numerical results of static bending and free vibration of functionally graded porous(FGP) variable-thickness plates by using an edge-based smoothed finite element method(ES... The main purpose of this paper is to present numerical results of static bending and free vibration of functionally graded porous(FGP) variable-thickness plates by using an edge-based smoothed finite element method(ES-FEM) associate with the mixed interpolation of tensorial components technique for the three-node triangular element(MITC3), so-called ES-MITC3. This ES-MITC3 element is performed to eliminate the shear locking problem and to enhance the accuracy of the existing MITC3 element. In the ES-MITC3 element, the stiffness matrices are obtained by using the strain smoothing technique over the smoothing domains formed by two adjacent MITC3 triangular elements sharing an edge. Materials of the plate are FGP with a power-law index(k) and maximum porosity distributions(U) in the forms of cosine functions. The influences of some geometric parameters, material properties on static bending, and natural frequency of the FGP variable-thickness plates are examined in detail. 展开更多
关键词 Functionally graded porous(FGP)plates Edge-based smoothed finite element method(ES-FEM) Mixed interpolation of tensorial components(MITC) Static bending Free vibration
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Investigation of the Free Vibrations of Radial Functionally Graded Circular Cylindrical Beams Based on Differential Quadrature Method 被引量:1
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作者 Xiaojun Huang Liaojun Zhang +2 位作者 Renyu Ge Hanbo Cui Zhedong Xu 《Computer Modeling in Engineering & Sciences》 SCIE EI 2022年第7期23-41,共19页
In the current research,an effective differential quadrature method(DQM)has been developed to solve natural frequency and vibration modal functions of circular section beams along radial functional gradient.Based on t... In the current research,an effective differential quadrature method(DQM)has been developed to solve natural frequency and vibration modal functions of circular section beams along radial functional gradient.Based on the high-order theory of transverse vibration of circular cross-section beams,lateral displacement equation was reconstructed neglecting circumferential shear stress.Two equations coupled with deflection and rotation angles were derived based on elastic mechanics theory and further simplified into a constant coefficient differential equation with natural frequency as eigenvalue.Then,differential quadrature method was applied to transform the eigenvalue problem of the derived differential equation into a set of algebraic equation eigenvalue problems.Natural frequencies of the free vibrations of cylindrical beams with circular cross-sections were calculated at one time,and corresponding modal functions were solved together.The obtained numerical results indicated that the natural frequencies of functionally graded(FG)circular cylindrical beams obtained using differential quadrature method agreed with the results reported in related literatures.In addition,influences of varying gradient parameters on the modal shapes of circular cylindrical beams were found to be strongly consistent with previous studies.Numerical results further validated the feasibility and accuracy of the developed differential quadrature method in solving the transverse vibration of FG circular cross-section beams. 展开更多
关键词 Functionally graded materials circular cylindrical beams natural frequency modal function differential quadrature method
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Swelling-induced finite bending of functionally graded pH-responsive hydrogels:a semi-analytical method 被引量:1
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作者 M.SHOJAEIFARD M.R.BAYAT M.BAGHANI 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2019年第5期679-694,共16页
Recently, pH-sensitive hydrogels have been utilized in the diverse applications including sensors, switches, and actuators. In order to have continuous stress and deformation ?elds, a new semi-analytical approach is d... Recently, pH-sensitive hydrogels have been utilized in the diverse applications including sensors, switches, and actuators. In order to have continuous stress and deformation ?elds, a new semi-analytical approach is developed to predict the swelling induced?nite bending for a functionally graded(FG) layer composed of a pH-sensitive hydrogel,in which the cross-link density is continuously distributed along the thickness direction under the plane strain condition. Without considering the intermediary virtual reference,the initial state is mapped into the deformed con?guration in a circular shape by utilizing a total deformation gradient tensor stemming from the inhomogeneous swelling of an FG layer in response to the variation of the pH value of the solvent. To enlighten the capability of the presented analytical method, the ?nite element method(FEM) is used to verify the accuracy of the analytical results in some case studies. The perfect agreement con-?rms the accuracy of the presented method. Due to the applicability of FG pH-sensitive hydrogels, some design factors such as the semi-angle, the bending curvature, the aspect ratio, and the distributions of deformation and stress ?elds are studied. Furthermore, the tangential free-stress axes are illustrated in deformed con?guration. 展开更多
关键词 pH-sensitive hydrogel functionally graded(FG)layer finite bending semianalytical solution finite element method(FEM)
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