Die design for cold precision forging of bevel gear based on finite element method

The finite element analysis （FEA） software Ansys was employed to study the stress state of the dies of both plane and non-plane parting face structures with uniform interference and the die of plane parting face structure with non-uniform interference. Considering the symmetry of the die, a half gear tooth model of the two-ring assembled die with 2.5 GPa inner pressure was constructed. Four paths were defined to investigate the stress state at the bottom comer of the die where stress concentration was serious. FEA results show that the change of parting face from non-plane to plane can greatly reduce the stress at the teeth tips of the die so that the tip fracture is avoided. The interference structure of the die is the most important influencing factor for the stress concentration at the bottom comer. When non-uniform interference is adopted the first principal stress at the comer on the defined paths of the die is much lower than that with uniform interference. The bottom hole radius is another important influencing factor for the comer stress concentration. The first principal stress at the comer of the plane parting face die with non-uniform interference is reduced from 2.3 to 1.9 GPa when the hole radius increases from 12.5 to 16.0 mm. The optimization of the die structure increases the life of the die from 100 to 6 000 hits.

New Finite Elements in Shear Stress Analysis of Saint Venant′s Torsional Loaded Beam Structures

Recent engineering design as well as material processing on the optimization procedure are based and computeroriented. Finite element stress and sensitivity analysis are the most important things in such modern determinationof optimal solution. According to high computer capacity finite element continuum discretization and load applicationindependent of the coming fields become unlimited. This paper deals with the development of a new finite elementsgeneration used in shear stress analysis caused by S.Venant′s torsional load and bending with shear. Their stiffnessmatrices and load vectors on the basis of their geometrical properties are derived. For justification of new finiteelements application some examples are presented.

Design and Optimization of Dual-Winding Fault-Tolerant Permanent Magnet Motor

To improve the performance of the traditional fault-tolerant permanent magnet(PM)motor,the design and optimal schemes of dual-winding fault-tolerant permanent magnet motor(DWFT-PMM)are proposed and investigated.In order to obtain small cogging torque ripple and inhibiting the short-circuit current,the air gap surface shape of the PM and the anti short-circuits reactance parameters are designed and optimized.According to the actual design requirements of an aircraft electrical actuation system,the parameters,finite element analysis and experimental verification of the DWFT-PMM after optimal design are presented.The research results show that the optimized DWFT-PMM owns the merits of strong magnetic isolation,physics isolation,inhibiting the short circuit current,small cogging torque ripple and high fault tolerance.

Investigation into precision engineering design and development of the next-generation brake discs using Al/SiC metal matrix composites

Substantially lightweight brake discs with high wear resistance are highly desirable in the automotive industry.This paper presents an investigation of the precision-engineering design and development of automotive brake discs using nonhomogeneous Al/SiC metal-matrixcomposite materials.The design and development are based on modeling and analysis following stringent precision-engineering principles,i.e.,brake-disc systems that operate repeatably and stably over time as enabled by precision-engineering design.The design and development are further supported by tribological experimental testing and finite-element simulations.The results show the industrial feasibility of the innovative design approach and the application merits of using advanced metal-matrix-composite materials for next-generation automotive and electric vehicles.

Web-Based Synthetic Optimization Design System of Micro-Components

In order to meet the requirement of network synthesis optimization design for a micro component, a three-level information frame and functional module based on web was proposed. Firstly, the finite element method （FEM） was used to analyze the dynamic property of coupled-energy-domain of virtual prototype instances and to obtain some optimal information data. Secondly, the rough set theory （RST） and the genetic algorithm （GA） were used to work out the reduction of attributes and the acquisition of principle of optimality and to confirm key variable and restriction condition in the synthesis optimization design. Finally, the regression analysis （RA） and GA were used to establish the synthesis optimization design model and carry on the optimization design. A corresponding prototype system was also developed and the synthesis optimization design of a thermal actuated micro-pump was carded out as a demonstration in this paper.

轮毂轴承单元密封结构优化设计及试验验证

针对轮毂轴承单元密封结构产生的摩擦力矩占比过大的问题,提出了将密封材料由氟橡胶改进为丁腈橡胶,密封结构减少一个接触唇的改进措施,并通过优化得到最优密封中间唇参数为唇倾斜角65°、唇厚0.6 mm、唇长3.8 mm、过盈量0.35 mm。将密封改进后的轮毂轴承单元进行了密封圈应力、漏脂试验、泥浆试验的仿真分析并通过试验进行验证,结果表明,优化后的轴承应力均满足材料许用应力要求,未出现漏脂现象,油脂含水量增加小于3%,启动、动态摩擦力矩分别降低了24.3%,22.1%,证明了优化后密封结构的可靠性。

基于Kriging模型的锥形气体静压轴承优化设计

针对如何提升小孔节流式锥形气体静压轴承综合性能的问题,以气浮电主轴用锥形气体静压轴承承载力最大、气体消耗量最小为优化目标,考虑轴承尺寸和工况要求的约束条件,采用最优拉丁超立方法选取设计点,通过有限元法计算样本集,利用2种提高精度的加点策略构建针对优化目标的改进Kriging代理模型,最终使用非支配排序遗传算法获得最优解集。根据工况要求,通过权重系数法提出了3种优化方案,优化方案的气体消耗量分别降低至初始设计的28.85%,56.08%和73.87%;承载力则分别提升至初始设计的1.14,2.16和2.44倍;3种优化方案在中高转速下的性能提升会更加明显。另外,提高轴承锥度虽然能提升承载力,但同时也会增加气体消耗量。

基于尺寸优化的电动铰接客车轻量化设计

新能源汽车目前最大的问题就是续航里程较短,轻量化设计可以在一定程度上增加续航里程和续航时间,对于传统燃油车来说,还能够降低排放和油耗。文章以某型号18 m铰接电动客车为例,利用有限元软件,基于尺寸优化对整车骨架进行轻量化设计,最终电动铰接客车比原先骨架减重0.6t,减重率达到了13.1%,效果显著。综上所述,文章提出并验证的轻量化方案是合理有效的,对新能源电动汽车改善动力性能、提升续航里程等方面具有现实意义。

基于ANSYS的单点式吊挂横梁的优化设计

随着直升机技术的发展,吊挂投放装置在直升机领域的运用越来越广泛,在情况危急时刻,对于吊挂安装速度的要求也越来越高。因此,吊挂投放系统的轻量化就极为重要。通过SolidWorks建立了吊挂模型,并联合ANSYS对其进行了有限元分析。结果表明,该单点式吊挂横梁有很大的优化空间。基于该横梁的参数,使用ANSYS对不同的轮廓进行优化;优化后横梁在满足国军标设计要求的情况下,质量减少了37.9%,达到了单点式吊挂投放系统轻量化的目的。

海管抛填装备重载偏心行走机构稳性优化设计

为了研制新型高效自动化的海底管道悬空治理抛投导向装备,保证大型重载抛投导向装备工作运动行走时的准确性、平衡性、可靠性和安全性,设计一种具有高度调节功能的重载偏心平衡轮组机构。根据抛投机构水平运动的相对位置调节轮组高度,平衡抛投偏心力矩和优化轮组负载受力分布,同时利用有限元软件计算分析新型的偏心平衡轮组机构关键零部件的强度。结果表明:轮轴关键部位的受力应力均比平衡前下降了61%,轮轴变形量减少了57%,在减少抛投机构因应力集中而损坏的风险的同时,验证了偏心运动平衡装置的有效性和安全性。研究成果可为新型高效自动化海底管道悬空治理抛投导向装备的研制提供理论和技术支撑。

Optimal design of pressure vessel using an improved genetic algorithm

As the idea of simulated annealing (SA) is introduced into the fitness function, an improved genetic algorithm (GA) is proposed to perform the optimal design of a pressure vessel which aims to attain the minimum weight under burst pressure con- straint. The actual burst pressure is calculated using the arc-length and restart analysis in finite element analysis (FEA). A penalty function in the fitness function is proposed to deal with the constrained problem. The effects of the population size and the number of generations in the GA on the weight and burst pressure of the vessel are explored. The optimization results using the proposed GA are also compared with those using the simple GA and the conventional Monte Carlo method.

Optimal design of a novel cylindrical sandwich panel with double arrow auxetic core under air blast loading

The increasing threat of explosions on the battle field and the terrorist action requires the development of more effective blast resistance materials and structures.Curved structure can support the external loads effectively by virtue of their spatial curvature.In review of the excellent energy absorption property of auxetic structure,employing auxetic structure as core material in curved sandwich shows the potential to improve the protection performance.In this study,a novel cylindrical sandwich panel with double arrow auxetic(DAA) core was designed and the numerical model was built by ABAQUS.Due to the complexity of the structure,systematic parameter study and optimal design are conducted.Two cases of optimal design were considered,case1 focuses on reducing the deflection and mass of the structure,while case2 focuses on reducing the deflection and increasing the energy absorption per unit mass.Parameter study and optimal design were conducted based on Latin Hypercube Sampling(LHD)method,artificial neural networks(ANN) metamodel and the nondominated sorting genetic algorithm(NSGA-Ⅱ).The Pareto front was obtained and the cylindrical DAA structure performed much better than its equal solid panel in both blast resistance and energy absorption capacity.Optimization results can be used as a reference for different applications.

Lightweight Design of Commercial Vehicle Cab Based on Fatigue Durability

To better improve the lightweight and fatigue durability performance of the tractor cab,a multi-objective lightweight design of the cab was carried out in this study.First,the finite element model of the cab with counterweight loading was established and then confirmed by the physical testing,and use the inertial reliefmethod to obtain stress distribution under unit load.The cab-frame rigid-flexible couplingmulti-body dynamicsmodelwas built by Adams/car software.Taking the cab airbag mount displacement and acceleration signals acquired on the proving ground as the desired signals and obtaining the fatigue analysis load spectrum through Femfat-Lab virtual iteration.The fatigue simulation analysis is performed in nCode based on the Miner linear fatigue cumulative damage theory.Then,with themass and fatigue damage values as the optimization objectives,the bending-torsional stiffness and first-order bending-torsional mode as constraints,the thickness variables are screed based on the sensitivity analysis.The experimental design was carried out using the Optimal Latin hypercube method,and the multi-objective optimal design of the cab was carried out using theKriging approximationmodel fitting and particle swarmalgorithm.The weight of the optimized cab is reduced by 7.8%on the basis of meeting the fatigue durability performance.Finally,a seven-axis road simulation test rig was designed to verify its fatigue durability.The results show the optimized cab can consider both lightweight and durability.

Lightweight design of peanut sowing machine frame based on finite element analysis

In order to reduce the weight and energy consumption of the whole machine against the heavy mechanical structure and excessive strength redundancy in current small-scale peanut seeders with one ridge and two rows,a finite element model of the frame was established and the static finite element analysis and modal analysis were conducted with ANSYS Workbench.Sensitivity analysis that focuses on the size of intermediate support beams and other components was performed so as to set up a multi-objective optimization model.Then a size optimization and multi-objective optimization collaborative scheme was adopted so that the target was optimized by the Seagull Optimization Algorithm(SOA)to obtain the optimal solution.Based on the results of the finite element analysis,the mechanical structure of the peanut seeder was optimized for lightweight design.Furthermore,response surface plots and static structural analysis were applied for validation.It turned out that the maximum stress of the optimized structure was less than the allowable stress;the weight of the frame reduced by 32.5%after optimization;and the first-order natural frequency did not coincide with the engine input speed or working speed,thus no resonance will occur.Field experiments showed that the qualified rate of row spacing was≥96%when operating at different speeds of different types of seeders;The seeding depth operation performance was stable,with an average qualified rate of seeding depth of≥92%;The performance of the seeders was also stable and reliable due to the lightweight prototype structure.The research outcomes can provide an effective technical reference and theoretical basis for the lightweight design of peanut seeders and for its continuous improvement as well in the future.

Design on the Prestressed Concrete Frame Beam-column

A bidirectional ribbed concrete beam slab structure was widly adopted for the upper space of industrial buildings.To maintain ample space and minimize the presence of conventional columns,a bidirectional prestressed concrete beam is often employed.The intersection node of the prestressed concrete frame beam column was characterized by a high density of steel reinforcement,significant structural loads,and complex construction requirements.To ensure the quality,safety,and progress of prestressed frame beamcolumn intersection nodes during construction,this article proposed a new technology for constructing such nodes,which includes setting the tensioning and haunching ends of nodes at different positions,using ABAQUS finite element software to optimize the design of cross-sectional dimensions,conducting stress analysis simulations.

Application of Improved RSM in the Optimization of Automotive Frontal Crashworthiness

Based on the vehicle front crash finite element analysis, it shows that there is a large acceleration, so it needs further optimization. In order to improve the performance of vehicle collision, eight parts were selected which have large impact for the result, its thickness as design variables to the right of the B-pillar acceleration peak of optimization goal;17 sample points were selected by Latin hypercube sampling method. Many structure parameters are optimized using sequential quadratic program (SQP) based on the surrogate model. The results show that the improved RSM has high accuracy;the right B-pillar acceleration reduced approximately 22.8%, reached the expected objective and was more conducive to the occupant safety.

On Hybrid Computer-Aided Tools to Interface Design Data

Recognizing the drawbacks of stand-alone computer-aided tools in engineering, several hybrid systems are suggested with varying degree of success. In transforming the design concept to a finished product, in particular, smooth interfacing of the design data is crucial to reduce product cost and time to market. Having a product model that contains the complete product description and computer-aided tools that can understand each other are the primary requirements to achieve the interfacing goal. This article discusses the development methodology of hybrid engineering software systems with particular focus on application of soft computing tools such as genetic algorithms and neural networks. Forms of hybridization options are discussed and the applications are elaborated using two case studies. The forefront aims to develop hybrid systems that combine the strong side of each tool, such as, the learning, pattern recognition and classification power of neural networks with the powerful capacity of genetic algorithms in global search and optimization. While most optimization tasks need a certain form of model, there are many processes in the mechanical engineering field that are difficult to model using conventional modeling techniques. The proposed hybrid system solves such difficult-to-model processes and contributes to the effort of smooth interfacing design data to other downstream processes.

Optimal Design of Rotary Tool based on ANSYS Workbench

Rotary tool of garbage crusher is the key component of the whole mechanism, which is of vital importance to tool design and analysis. Based on ANSYS Workbench 3D modeling, we carried on finite element analysis to tool, and used the method of goal driven optimization to optimize the rotary tool. The optimization proves that the optimized maximum equivalent stress is 544.14 MPa, the quality is less, and the optimized rotary tool size is more reasonable. So it provided reasonable and scientific reference frame to the structural design of rotary tool.

高空台流量管新型篦齿密封特性分析及结构优化设计

针对高空台流量管与导流盆连接结构减小气体泄漏、避免出现反向进气压力过大导致结冰的设计要求,开展不同内径流量管新型篦齿密封特性及结构参数优化研究。建立了高空台新型流量管篦齿密封结构有限元模型,并开展了新型流量管篦齿密封结构泄漏特性实验研究。基于数值模拟与试验,研究了流量管内径对密封性能的影响规律。根据Box-Behnken响应面设计法,选取不同流量管内径下的密封间隙、控制口数量以及孔型出口数量为优化参数,进行新型篦齿密封结构参数优化设计研究。结果表明:仿真泄漏量与试验值相比最大误差不超过7%,证明了本文仿真模型的有效性;当结构内径由1 m增大到3 m,密封泄漏量由0.021 kg/s逐渐增加到0.162 kg/s,增幅高达671.4%;内径1 m,2 m和3 m篦齿密封结构经优化后,最大流速分别减小了16.1%,14.3%和9.7%,泄漏量分别降低50.74%,98.50%和97.52%。本文研究为高空台新型流量管篦齿密封结构优化设计提供了有效方法,也为流量管尺寸规范化设计提供了技术支撑。

基于正交试验的硅基MEMS齿形后坐保险机构参数敏感性

为了对硅基MEMS后坐保险机构进行优化设计和性能研究,基于正交试验与有限元仿真软件相结合的方法,选择齿高、齿宽、弹簧线宽、闭锁梁宽、锁钩间距、初始距离这6个设计参数,对后坐保险机构在正常发射和勤务跌落载荷下的位移和应力的影响进行参数敏感性分析。通过极差分析与方差分析,定量地给出了后坐保险机构各参数对结构在不同冲击载荷下的影响。结果表明,齿高的影响最显著,是影响后坐保险机构位移与应力响应的最主要因素;初始距离、弹簧线宽、齿宽是影响勤务跌落最大位移的次要因素;其他因素均对正常发射与勤务跌落载荷下位移和应力不显示显著性。在相对少的试验次数中定量得出不同设计参数对硅基后坐保险机构的影响大小,对多参数双目标的硅基后坐保险机构优化提供了一定的参考。