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Design and additive manufacturing of bionic hybrid structure inspired by cuttlebone to achieve superior mechanical properties and shape memory function
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作者 Luhao Yuan Dongdong Gu +8 位作者 Xin Liu Keyu Shi Kaijie Lin He Liu Han Zhang Donghua Dai Jianfeng Sun Wenxin Chen Jie Wang 《International Journal of Extreme Manufacturing》 SCIE EI CAS CSCD 2024年第5期189-206,共18页
Lightweight porous materials with high load-bearing,damage tolerance and energy absorption(EA)as well as intelligence of shape recovery after material deformation are beneficial and critical for many applications,e.g.... Lightweight porous materials with high load-bearing,damage tolerance and energy absorption(EA)as well as intelligence of shape recovery after material deformation are beneficial and critical for many applications,e.g.aerospace,automobiles,electronics,etc.Cuttlebone produced in the cuttlefish has evolved vertical walls with the optimal corrugation gradient,enabling stress homogenization,significant load bearing,and damage tolerance to protect the organism from high external pressures in the deep sea.This work illustrated that the complex hybrid wave shape in cuttlebone walls,becoming more tortuous from bottom to top,creates a lightweight,load-bearing structure with progressive failure.By mimicking the cuttlebone,a novel bionic hybrid structure(BHS)was proposed,and as a comparison,a regular corrugated structure and a straight wall structure were designed.Three types of designed structures have been successfully manufactured by laser powder bed fusion(LPBF)with NiTi powder.The LPBF-processed BHS exhibited a total porosity of 0.042% and a good dimensional accuracy with a peak deviation of 17.4μm.Microstructural analysis indicated that the LPBF-processed BHS had a strong(001)crystallographic orientation and an average size of 9.85μm.Mechanical analysis revealed the LPBF-processed BHS could withstand over 25000 times its weight without significant deformation and had the highest specific EA value(5.32 J·g^(−1))due to the absence of stress concentration and progressive wall failure during compression.Cyclic compression testing showed that LPBF-processed BHS possessed superior viscoelastic and elasticity energy dissipation capacity.Importantly,the uniform reversible phase transition from martensite to austenite in the walls enables the structure to largely recover its pre-deformation shape when heated(over 99% recovery rate).These design strategies can serve as valuable references for the development of intelligent components that possess high mechanical efficiency and shape memory capabilities. 展开更多
关键词 additive manufacturing laser powder bed fusion bionic structure CUTTLEBONE mechanical properties shape memory function
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STRUCTURAL HEALTH MONITORING IN COMPOSITE MATERIALS USING EMBEDDED SHAPE MEMORY ALLOY(SMA) WIRE SENSORS
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作者 QIU Zixue YAO Xingtian COSTAS Soutis 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2006年第3期446-450,共5页
Shape memory alloy (SMA) materials possess completely superelasticity or pseudoelasticity above the austenite finish temperature and many unique mechanical, thermal, thermal-mechanical and electrical properties comp... Shape memory alloy (SMA) materials possess completely superelasticity or pseudoelasticity above the austenite finish temperature and many unique mechanical, thermal, thermal-mechanical and electrical properties compared with other conventional materials. Many studies have reported that the superelastic and hysteresis properties of the SMA materials can absorb energies coming from external excitations or sudden impacts. In addition, due to the special electrical properties of NiTi superelastic wires, they can also be used as strain-sensing element to monitor structural health conditions. Composite laminated specimens embedded with SMA wire sensors are fabricated and detailed testing system is designed such as multi-parameters measuring for impact and weak signal processing for SMA sensor. Low velocity impact test shows that SMA wire sensors embedded in fiber-reinforced plastic (FRP) laminate can be well used to monitor impact responses, such as the location of impact damage, impact degree, and strain distribution. Experimental results and theoretical predictions reveal almost the same. Comparing with other method, a simple, economic and reliable technique method monitoring important engineering structures on line is provided. 展开更多
关键词 shape memory alloy(SMA) structural health monitoring Sensor
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INTEGRATION SHAPE AND SIZING OPTIMIZATION OF COMPOSITE WING STRUCTURE BASED ON RESPONSE SURFACE METHOD 被引量:7
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作者 王伟 杨伟 常楠 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2008年第2期94-100,共7页
An effective optimization method for the shape/sizing design of composite wing structures is presented with satisfying weight-cutting results. After decoupling, a kind of two-layer cycled optimization strategy suitabl... An effective optimization method for the shape/sizing design of composite wing structures is presented with satisfying weight-cutting results. After decoupling, a kind of two-layer cycled optimization strategy suitable for these integrated shape/sizing optimization is obtained. The uniform design method is used to provide sample points, and approximation models for shape design variables. And the results of sizing optimization are construct- ed with the quadratic response surface method (QRSM). The complex method based on QRSM is used to opti- mize the shape design variables and the criteria method is adopted to optimize the sizing design variables. Compared with the conventional method, the proposed algorithm is more effective and feasible for solving complex composite optimization problems and has good efficiency in weight cutting. 展开更多
关键词 composite structures shape optimization WINGS sizing optimization response surface method
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Analysis on the Composition and Structure of Branches of Two Kinds of Tree Shapes in Korla Fragrant Pear 被引量:2
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作者 成小龙 廖康 +4 位作者 李楠 赵世荣 孙慧瑛 曼苏尔.那斯尔 刘娟 《Agricultural Science & Technology》 CAS 2013年第7期954-958,共5页
ObjectiveThe thesis aims at investigating the distribution and structural characteristics of various branches in canopy of Korla fragrant pear. MethodStatistic work and analysis were conducted on the numbers and distr... ObjectiveThe thesis aims at investigating the distribution and structural characteristics of various branches in canopy of Korla fragrant pear. MethodStatistic work and analysis were conducted on the numbers and distribution characteristics of various branches in each cubic lattice by using the canopy cellular method. ResultThe results showed that: The total number of scaffold branches of evacuation layered tree shape was 97, which mainly distributed in the lower layer and middle part of the canopy; the total number of scaffold branches of open-center tree shape was 94, which mainly distributed in the lower layer and middle part of the canopy. The total number of annual branches of evacuation layered tree shape was 3 920, which mainly distributed in the middle layer and outer part of the canopy; and the total number of annual branches of the open-center tree shape was 3 183, which mainly distributed in middle layer and outer part of the canopy. The total number of perennial branches of evacuation layered tree shape was 2 184, which mainly distributed in lower layer and outer part of the canopy; the total number of perennial branches of open-center tree shape was 1 444, which mainly distributed in middle layer and outer part of the canopy. ConclusionThe total number and the distribution positions of scaffold branches in the canopy of each tree shape were basically the same. The total numbers of annual branches of the two kinds of tree shapes were different, but the distribution positions were basically the same. The total numbers and the distribution positions of perennial branches in the canopy of the two kinds of tree shapes were different. 展开更多
关键词 Korla fragrant pear Tree shape Composition and structure of branch
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Meso-mechanical analyses of shape memory alloy wires reinforced smart structures with damages
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作者 胡自力 周晚林 《Journal of Southeast University(English Edition)》 EI CAS 2005年第1期97-101,共5页
The thermo-mechanical behaviors of shape memory alloy (SMA) wires reinforced smart structures with damages are analyzed through variational principle and meso-mechanical method.A governing equation on the structure is... The thermo-mechanical behaviors of shape memory alloy (SMA) wires reinforced smart structures with damages are analyzed through variational principle and meso-mechanical method.A governing equation on the structure is derived.Mathematical expressions on meso-displacement field,stress-strain field of typical element with damages are presented.A failure criterion for interface failure between SMA wires and matrix is established under two kinds of actuation which are dead-load and temperature,where the temperature is included in effective free restoring strain.In addition,there are some other composing factors in the failure criterion such as interface properties,thermodynamical properties of SMA,initial debonding length L-l,etc.The results are significant to understand structural strength self-adaptive control and failure mechanism of SMA wires reinforced smart structures with damages,and provide a theoretical foundation for further study on the integrity of SMA smart structures. 展开更多
关键词 smart structure damage shape memory alloy FAILURE meso-mechanical analysis variational principle
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Structural Design Optimization Using Isogeometric Analysis: A Comprehensive Review 被引量:11
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作者 Yingjun Wang Zhenpei Wang +1 位作者 Zhaohui Xia Leong Hien Poh 《Computer Modeling in Engineering & Sciences》 SCIE EI 2018年第12期455-507,共53页
Isogeometric analysis(IGA),an approach that integrates CAE into conventional CAD design tools,has been used in structural optimization for 10 years,with plenty of excellent research results.This paper provides a compr... Isogeometric analysis(IGA),an approach that integrates CAE into conventional CAD design tools,has been used in structural optimization for 10 years,with plenty of excellent research results.This paper provides a comprehensive review on isogeometric shape and topology optimization,with a brief coverage of size optimization.For isogeometric shape optimization,attention is focused on the parametrization methods,mesh updating schemes and shape sensitivity analyses.Some interesting observations,e.g.the popularity of using direct(differential)method for shape sensitivity analysis and the possibility of developing a large scale,seamlessly integrated analysis-design platform,are discussed in the framework of isogeometric shape optimization.For isogeometric topology optimization(ITO),we discuss different types of ITOs,e.g.ITO using SIMP(Solid Isotropic Material with Penalization)method,ITO using level set method,ITO using moving morphable com-ponents(MMC),ITO with phase field model,etc.,their technical details and applications such as the spline filter,multi-resolution approach,multi-material problems and stress con-strained problems.In addition to the review in the last 10 years,the current developmental trend of isogeometric structural optimization is discussed. 展开更多
关键词 Isogeometric ANALYSIS structural OPTIMIZATION shape OPTIMIZATION TOPOLOGY OPTIMIZATION sensitivity analysis.
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A new isolation device using shape memory alloy and its application for long-span structures 被引量:3
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作者 Ding Youliang Chen Xin +1 位作者 Li Aiqun Zuo Xiaobao 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2011年第2期239-252,共14页
The key points to consider in determining the effectiveness of using structural isolation with shape memory alloys (SMA) are the constitutive model, the SMA isolation device and the analysis method. In this paper, a... The key points to consider in determining the effectiveness of using structural isolation with shape memory alloys (SMA) are the constitutive model, the SMA isolation device and the analysis method. In this paper, a simplified constitutive model based on the classic theory of plasticity is proposed to simulate the behavior of the superelasticity of the SMA, in which the martensite volume fraction is considered as one of the state variables. Comparisons between simulation results and experimental results are made and indicate that the proposed constitutive model yields stress-strain curves that are in good agreement with the experimental ones. Thus, the proposed model can correctly simulate the yield mechanism and energy dissipation capacity of the SMA. Next, in order to make full use of the superelasticity of SMA, a new SMA isolator composed of pre-tensioned SMA bars is presented. Then, a finite element analytical model is established to simulate the behavior of the SMA isolator according to its configuration and simplified constitutive model. Finally, a simplified design method for long-span structures installed with SMA isolators is proposed, which is further used to investigate the isolation effects of a space grid structure. Results show that the SMA isolator can reduce the seismic responses of the structure effectively, which indicates the effectiveness of the proposed SMA isolation method. 展开更多
关键词 shape memory alloy super-elasticity constitutive model seismic response structural isolation space gridstructure
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Mechanical Behavior and Shape Optimization of Lining Structure for Subsea Tunnel Excavated in Weathered Slot 被引量:2
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作者 李鹏飞 周晓军 《China Ocean Engineering》 SCIE EI CSCD 2015年第6期875-890,共16页
Subsea tunnel lining structures should be designed to sustain the loads transmitted from surrounding ground and groundwater during excavation. Extremely high pore-water pressure reduces the effective strength of the c... Subsea tunnel lining structures should be designed to sustain the loads transmitted from surrounding ground and groundwater during excavation. Extremely high pore-water pressure reduces the effective strength of the country rock that surrounds a tunnel, thereby lowering the arching effect and stratum stability of the structure. In this paper, the mechanical behavior and shape optimization of the lining structure for the Xiang'an tunnel excavated in weathered slots are examined. Eight cross sections with different geometric parameters are adopted to study the mechanical behavior and shape optimization of the lining structure. The hyperstatic reaction method is used through finite element analysis software ANSYS. The mechanical behavior of the lining structure is evidently affected by the geometric parameters of crosssectional shape. The minimum safety factor of the lining structure elements is set to be the objective function. The efficient tunnel shape to maximize the minimum safety factor is identified. The minimum safety factor increases significantly after optimization. The optimized cross section significantly improves the mechanical characteristics of the lining structure and effectively reduces its deformation. Force analyses of optimization process and program are conducted parametrically so that the method can be applied to the optimization design of other similar structures. The results obtained from this study enhance our understanding of the mechanical behavior of the lining structure for subsea tunnels. These results are also beneficial to the optimal design of lining structures in general. 展开更多
关键词 subsea tunnel lining structure shape optimization safety factor hyperstatic reaction method
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Compressive mechanical properties and shape memory effect of NiTi gradient lattice structures fabricated by laser powder bed fusion 被引量:9
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作者 Wei Chen Dongdong Gu +3 位作者 Jiankai Yang Qin Yang Jie Chen Xianfeng Shen 《International Journal of Extreme Manufacturing》 SCIE EI CAS 2022年第4期189-205,共17页
Laser additive manufacturing (AM) of lattice structures with light weight, excellent impact resistance, and energy absorption performance is receiving considerable attention in aerospace, transportation, and mechanica... Laser additive manufacturing (AM) of lattice structures with light weight, excellent impact resistance, and energy absorption performance is receiving considerable attention in aerospace, transportation, and mechanical equipment application fields. In this study, we designed four gradient lattice structures (GLSs) using the topology optimization method, including the unidirectional GLS, the bi-directional increasing GLS, the bi-directional decreasing GLS and the none-GLS. All GLSs were manufactureed by laser powder bed fusion (LPBF). The uniaxial compression tests and finite element analysis were conducted to investigate the influence of gradient distribution features on deformation modes and energy absorption performance of GLSs. The results showed that, compared with the 45° shear fracture characteristic of the none-GLS, the unidirectional GLS, the bi-directional increasing GLS and the bi-directional decreasing GLS had the characteristics of the layer-by-layer fracture, showing considerably improved energy absorption capacity. The bi-directional increasing GLS showed a unique combination of shear fracture and layer-by-layer fracture, having the optimal energy absorption performance with energy absorption and specific energy absorption of 235.6 J and 9.5 J g-1 at 0.5 strain, respectively. Combined with the shape memory effect of NiTi alloy, multiple compression-heat recovery experiments were carried out to verify the shape memory function of LPBF-processed NiTi GLSs. These findings have potential value for the future design of GLSs and the realization of shape memory function of NiTi components through laser AM. 展开更多
关键词 additive manufacturing laser powder bed fusion gradient lattice structures deformation behavior shape memory effect
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Optimum Design of Structure Shape for Offshore Jacket Platforms 被引量:2
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作者 封盛 宋玉普 张日向 《China Ocean Engineering》 SCIE EI 2000年第4期435-445,共11页
With the introduction of the design variables of nodal coordinates, which reflect the embedded depth of the pile and the jacket bed height, a shape optimum design model for offshore jacket platforms is established. A ... With the introduction of the design variables of nodal coordinates, which reflect the embedded depth of the pile and the jacket bed height, a shape optimum design model for offshore jacket platforms is established. A sequential two-level optimum algorithm is developed based on the design variable gradation. On the basis of the finite element method, the sensitivity of the objective function and nodal displacement is analyzed. As an example, the BZ281 oil storage offshore platform, which ties in the Bohai oil field, is designed with the shape optimum model. The results are compared with the cross-section optimum design. The tendency of design variables and its reasons in the two methods are analyzed. In the shape optimum design, the value of objective function is obviously smaller than that of the initial design and the cross-section optimum design. Therefore, the advantage of structure shape optimum design for jacket platforms is remarkable. 展开更多
关键词 offshore jacket platform structure shape optimization sensitivity analysis
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Extraction of mode shapes of beam-like structures from the dynamic response of a moving mass 被引量:2
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作者 Yao Zhang Longqi Wang +1 位作者 Haisheng Zhao Seng Tjhen Lie 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2019年第3期664-673,共10页
This paper proposes an approach to extract the mode shapes of beam-like structures from the dynamic response of a moving mass. When a mass passes through a beam containing several artificially installed humps, its ver... This paper proposes an approach to extract the mode shapes of beam-like structures from the dynamic response of a moving mass. When a mass passes through a beam containing several artificially installed humps, its vertical acceleration can be recorded. After applying fast Fourier transformation to the dynamic response, one can extract the mode shapes of the beam. The surface roughness was neglected compared to the humps and its adverse effect on the extraction was reduced. The passing mass performs as both “exciter” and “massage receiver”;therefore, this method requires only one single accelerometer, making it more convenient and time saving in practice. Moreover, to estimate the possible error in extracting mode shapes, a wavenumber domain filtering technique is used to reconstruct the general profiles of mode shapes. Experimental validation of this approach in laboratory scale was conducted. The experimental results show that the proposed method performs well in extracting lower order mode shapes. It should also be noted that the passing mass can not have a very high velocity (e.g. 80 mm/s), otherwise the mass may jump and separate from the beam, and the proposed method may fail to identify mode shapes. 展开更多
关键词 Mode shape Beam-like structurES MOVING mass Artificially installed humps Fast FOURIER TRANSFORMATION
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Multiscale Isogeometric Topology Optimization with Unified Structural Skeleton 被引量:3
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作者 Chen Yu Qifu Wang +1 位作者 Chao Mei Zhaohui Xia 《Computer Modeling in Engineering & Sciences》 SCIE EI 2020年第3期779-803,共25页
This paper proposes a multiscale isogeometric topology optimization(ITO)method where the configuration and layout of microstructures are optimized simultaneously.At micro scale,a shape deformation method is presented ... This paper proposes a multiscale isogeometric topology optimization(ITO)method where the configuration and layout of microstructures are optimized simultaneously.At micro scale,a shape deformation method is presented to transform a prototype microstructure(PM)for obtaining a series of graded microstructures(GMs),where microstructural skeleton based on the level set framework is applied to retain more topology features and improve the connectability.For the macro scale calculation,the effective mechanical properties can be estimated by means of the numerical homogenization method.By adopting identical non-uniform rational basis splines(NURBS)as basis functions for both parameterized level set model and isogeometric calculation model,the isogeometric analysis(IGA)is integrated into the level set method,which contributes to improving the accuracy and efficiency.Numerical examples demonstrate that,the proposed method is effective in improving the performance and manufacturability. 展开更多
关键词 Isogeometric analysis topology optimization shape deformation method structural skeleton level set method.
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Influence of a liquid-filled compartment structure on the incoming shaped charge jet stability 被引量:2
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作者 X.D.Zu Z.X.Huang +2 位作者 Z.W.Guan X.C.Yin Y.M.Zheng 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2021年第2期571-582,共12页
Liquid-filled compartment structure consists of a bulk steel plate with matrix blind holes which are filled with liquid and a steel front plate to seal up the liquid with rings and bolts.The liquid-filled compartment ... Liquid-filled compartment structure consists of a bulk steel plate with matrix blind holes which are filled with liquid and a steel front plate to seal up the liquid with rings and bolts.The liquid-filled compartment structure can resist the shaped charge warhead effectively.This paper presents experimental and theoretical investigations of the penetration ability of the residual shaped charge jet emerging from the liquid-filled compartment structure after the penetration process at different impact angles.On the basis of shock wave propagation theory,the influence of the liquid-filled compartment structure on jet stability is analysed.The interferences of the liquid backflow caused by a reflected shock wave and a back plate on jet stability under different impact angles are also examined.In addition,the range of the disturbed velocity segments of the jet at different impact angles and the penetration ability of the residual jet are obtained.A theoretical model is validated against the experimental penetration depths. 展开更多
关键词 Compartment structure shaped charge jet Shock wave DISTURBANCE STABILITY
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Study on liquid-filled structure target with shaped charge vertical penetration 被引量:1
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作者 Min Guo Xu-dong Zu +1 位作者 Xiao-jun Shen Zheng-xiang Huang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2019年第6期861-867,共7页
Based on the characteristic expanded hole of a shaped charge jet(SCJ) for target penetration and the reflow characteristics of liquids,the liquid-filled structure of a target disturbs the stability of the SCJ acquired... Based on the characteristic expanded hole of a shaped charge jet(SCJ) for target penetration and the reflow characteristics of liquids,the liquid-filled structure of a target disturbs the stability of the SCJ acquired in two independent parts.The interference jet speed interval,the escape jet speed interval,and the surplus depth are calculated on the basis of the virtual origin theory.The experimental results,including the velocity of the escaped jet tip and the surplus depth of penetration,are consistent with the theoretical results.Experiments show that the theory can describe the interaction process of the target with a shaped charge jet. 展开更多
关键词 shaped charge Liquid-filled structure target Disturbed jet Escape jet
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MESO-MECHANICAL ANALYSIS OF SHAPE MEMORY ALLOY REINFORCED SMART STRUCTURE WITH DAMAGE 被引量:1
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作者 Hu Zili 《Acta Mechanica Solida Sinica》 SCIE EI 2006年第3期189-195,共7页
The mechanical behaviors of shape memory alloy (SMA) wires reinforced smart structure with damage were analyzed through the variational principle, a governing equation for the structure was derived, mathematical exp... The mechanical behaviors of shape memory alloy (SMA) wires reinforced smart structure with damage were analyzed through the variational principle, a governing equation for the structure was derived, mathematical expressions for the meso-displacement field, stressstrain field of typical element with damage were presented, and a failure criterion for interface failure between SMA wires and matrix was established under two kinds of actuation which are dead-load and temperature, where the temperature is included in effective free restoring strain. In addition, there are some other composing factors in the failure criterion such as the interface properties, dynamical properties of SMA, initial debonding length L - l etc. The results are significant to understand structural strength self-adapted control and failure mechanism of SMA wires reinforced smart structure with damage. 展开更多
关键词 smart structures DAMAGE shape memory alloy FAILURE meso-mechanical analysis variational principle
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Study on jet formation behavior and optimization of trunconical hypercumulation shaped charge structure 被引量:1
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作者 Chao Ge Zhuojun Qu +2 位作者 Jin Wang Die Hu Yong Zhang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2023年第3期196-206,共11页
Combining the methods of theoretical,numerical and experimental,this research focuses on the jet formation behavior and optimization of trunconical hypercumulation shaped charge structure.With the three-stage division... Combining the methods of theoretical,numerical and experimental,this research focuses on the jet formation behavior and optimization of trunconical hypercumulation shaped charge structure.With the three-stage division,formation theory of trunconical hypercumulation shaped charge jet is established based on micro element method.By dimensional analysis,main control parameters are identified and their effect on jet formation are analyzed.Through numerical modelling and orthogonal optimization method,influence of the factors and their levels over the indicators of jet tip velocity and jet length as well as order of the significance of each factor and level are obtained.Penetration experiments of trunconical hypercumulation shaped charge based on the orthogonal optimization reveals its advantage over traditional conical shaped charge structure,and finally determines the optimal influence factor level combination.The research and results would provide useful guide for the design and application of trunconical hypercumulation shaped charge structure. 展开更多
关键词 structurE shapeD CHARGE
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Influence of shaped charge structure parameters on the formation of linear explosively formed projectiles 被引量:1
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作者 Tian-bao Ma Jing Liu Qi Wang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2022年第10期1863-1874,共12页
The research of LEFP(linear explosive forming projectile)is of great value to the development of new warhead due to its excellent performance.To further improve the damage ability of the shaped charge warhead,a specia... The research of LEFP(linear explosive forming projectile)is of great value to the development of new warhead due to its excellent performance.To further improve the damage ability of the shaped charge warhead,a special shell overhanging structure was designed to increase the charge based on the traditional spherical charge,in which case the crushing energy of LEFP could be guaranteed.LS-DYNA was used to simulate different charge structures obtained by changing the number of detonation points,the length of shell platform,the radius of curvature and the thickness of liner.The RSM(response surface model)between the molding parameters of LEFP and the structural parameters of charge was established.Based on RSM model,the structure of shaped charge was optimized by using multi-objective genetic algorithm.Meanwhile,the formation process of jet was analyzed by pulsed X-ray photography.The results show that the velocity,length-diameter ratio and specific kinetic energy of the LEFP were closely related to the structural parameters of the shaped charge.After the optimization of charge structure,the forming effect and penetration ability of LEPP had been significantly improved.The experimental data of jet velocity and length were consistent with the numerical results,which verifies the reliability of the numerical results. 展开更多
关键词 LEFP Numerical simulation shaped charge structure optimization
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Isogeometric Analysis and Shape Optimization of Holed Structures via the Patch Removing Technique 被引量:1
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作者 Daoyuan Yu Shouyu Cai +1 位作者 Wenya Fan Lan Zhang 《Computer Modeling in Engineering & Sciences》 SCIE EI 2020年第9期787-806,共20页
In this study,a patch removing based Isogeometric analysis(PR-IGA)method is proposed to conduct the holed structural analysis with only one parametric domain,in which there are also no trimmed elements.The theoretical... In this study,a patch removing based Isogeometric analysis(PR-IGA)method is proposed to conduct the holed structural analysis with only one parametric domain,in which there are also no trimmed elements.The theoretical foundation of this novel patch removing approach is that any holed structure can be obtained by removing sub-patches(i.e.,the holes)from an intact base patch.Since the parametric domains of these patches are all meshed by rectangular grids,the elements in the resulted holed structural parametric domain could all be untrimmed rectangles under certain mapping conditions.To achieve the special condition,a systematic technique consisting of T-spline local refinement and control points substitution/adjustment is provided.Due to the intactness of parametric elements,the analysis procedure of holed structures based on the proposed PRIGA is quite simplified and efficient compared to traditional multi-patch and trimming schemes.Moreover,after the deduction of analytical sensitivities related to structural mass and mechanical responses,the PR-IGA is directly employed in the holed structural shape optimization to successfully eliminate the need for model transformation during modeling,analysis and optimization processes.Numerical examples involving analysis and shape optimization of complex holed structures are presented to demonstrate the effectiveness of the proposed method. 展开更多
关键词 Isogeometric analysis patch removing shape optimization holed structure
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Formation Mechanism of Curved Martensite Structures in Cu-based Shape Memory Alloys 被引量:2
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作者 Yujun BAI, Qiquan SHI,Guili GENG, Dongsheng SUN and Xiufang BIAN (Institute of Materials Engineering, Shandong University of Technology, Jinan 250061, China) 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2000年第1期79-81,共3页
The curved martensite structures have been observed in CuZnAI-based shape memory alloys by both transmission electron microscope and optical microscope. It was found that the curved martensite structures observed in a... The curved martensite structures have been observed in CuZnAI-based shape memory alloys by both transmission electron microscope and optical microscope. It was found that the curved martensite structures observed in as-solution treated, as-aged and as-trained alloys usually occurred around dislocation tangles or precipitate, at the plate boundary or grain boundary, and when the growing plates collided with each other or alternate mutually. 展开更多
关键词 Formation Mechanism of Curved Martensite structures in Cu-based shape Memory Alloys CU
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Influence of Shape and Size of Threshing Frame and Tobacco Grade on Leaf Strip Structure 被引量:2
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作者 CHEN Zhuang-yu HE Ze-jun +2 位作者 LI Ye-chun HUANG Jing HUANG Ya-fei 《Agricultural Science & Technology》 CAS 2020年第3期18-24,共7页
This paper focused on the influence of the shape and size of threshing frames as well as the grades of tobacco leaves on the structure of threshed leaves.The testing tobacco leaves all came from the hilly ecological r... This paper focused on the influence of the shape and size of threshing frames as well as the grades of tobacco leaves on the structure of threshed leaves.The testing tobacco leaves all came from the hilly ecological region of Nanling and belonged to burnt sweet,alcoholic sweet and scent category.The comprehensive evaluating value S was taken as the test index.Results showed that,without considering the influence of tobacco grade on leaf structure,the shapes of first-stage thresher five-link frames were all hexagons,and the combination with the sizes of 3.5,3.0,3.5,3.0,3.0 inches had the highest evaluating value S of 2.49.For tobacco grade C2FH,the shapes of first-stage thresher five-link frames were also hexagons,and the evaluating value S reached the highest value of 3.40 with sizes of 3.5,3.0,3.5,3.0,3.0 inches.Comprehensive analysis showed that:3.0 inch frame performed better in controlling the percentage of large-sized strips than 3.5 inch frame did;rhombic frames were better than hexagon frames in reducing the breakage rate of tobacco leaves;different shapes or sizes of nonadjacent two-link frames can help to improve the threshing quality. 展开更多
关键词 Threshing frame Leaf strip structure Percentage of medium-sized strips shape and size
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