共查询到15条相似文献,搜索用时 125 毫秒
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对某白车身建立有限元模,利用MSC Nastran软件进行扭转刚度和模态分析,在此基础上以车身重量为优化目标,在满足扭转刚度要求的条件下对零件厚度进行敏感度分析和优化分析,得到了符合设计要求的改进方案. 相似文献
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利用SFE Concept建立某轿车白车身的参数化模型,采用有限元法对白车身的静态弯曲和扭转刚度、主要低阶模态进行分析,并将仿真结果与试验结果进行对比。将参数化白车身与动力总成、底盘、闭合件连接后,仿真分析整车正面100%碰撞安全性能并验证有限元模型的有效性。提出通过相对灵敏度分析确定白车身非安全件设计变量的方法,采用最优拉丁超立方方法生成样本点,基于径向基神经网络方法拟合近似模型,以白车身非安全件和正碰安全件为轻量化对象,通过第二代非劣排序遗传算法对白车身进行多目标优化设计。结果表明:在白车身静态弯曲刚度降低3.60%、静态扭转刚度降低3.91%、一阶弯曲模态固有频率降低0.09%、一阶扭转模态固有频率上升1.26%、正碰安全性能基本不变的情况下,白车身质量减少24.17 kg,减重7.42%,轻量化效果显著。 相似文献
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汽车车身静态刚度测量 总被引:1,自引:0,他引:1
针对目前我国汽车车身刚度检测设备的落后现状,采用现代微机检测与控制技术开发了一种新型的汽车车身静态刚度测量系统;该系统采用精密测量技术,用DSP2407采集多路数据,并利用工业控制计算机进行数据处理,在线检测汽车车身的刚度状况并以红旗轿车为例,对其白车身进行弯曲变形和扭转变形试验,检测汽车车身的刚度状况;该项目填补了全自动检测汽车车身静态刚度的空白,为国内首创. 相似文献
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本文采用有限元结构分析软件Nastran对摩托车车架的模态、刚度进行优化,计算各个设计变量的灵敏度系数,并结合工程实际,找出了对车架第一阶模态频率和弯曲、扭转刚度值影响最大的因素。 相似文献
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车架质量占赛车整车质量的比例很大,其在轻量化方面存在可优化空间。利用CATIA设计一种钢管桁架结构和单体壳结构的复合式车架,在HyperMesh中建立有限元模型,对车架的单体壳部分进行尺寸优化,确定不同区域层合板的最佳厚度,最终得到的车架质量为21.8 kg,扭转刚度为4 057 N·m/(°),较纯钢管车架减重约5 kg,刚度提高约1倍,满足设计目标。 相似文献
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Gang-Won Jang Min-Su Yoon Jae Ha Park 《Structural and Multidisciplinary Optimization》2010,41(2):295-307
A new design for a lightweight flatbed trailer with high bending stiffness and torsional frequency is presented. The design
procedure consists of two main steps: topology optimization and thickness optimization. During topology optimization, a creative
frame layout different from existing ladder-type frames can be obtained by searching the best layout out of all possible layouts
of a simplified design domain model. After approximating the result of topology optimization as a thin-walled structure, the
approximated thicknesses of the plates are optimized to minimize the mass of a trailer. The bending stiffness and torsional
frequency obtained by topology optimization are set as design constraints for thickness optimization. Due to the closed cross-section,
the optimized trailer can efficiently increase the stiffness-to-mass ratio to a large extent. Discrete thicknesses are employed
as design variables for thickness optimization so that the thicknesses of the plates of a trailer can be included in those
of commercially available high-strength steel products. The final model has a 29% reduction in total mass, a 21% decrease
in mean compliance with a uniform bending load, and a 169% increase in torsional frequency. 相似文献
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Multi-objective optimization for bus body with strength and rollover safety constraints based on surrogate models 总被引:1,自引:1,他引:0
It is important to consider the performances of lightweight, stiffness, strength and rollover safety when designing a bus
body. In this paper, the finite element (FE) analysis models including strength, stiffness and rollover crashworthiness of
a bus body are first built and then validated by physical tests. Based on the FE models, the design of experiment is implemented
and multiple surrogate models are created with response surface method and hybrid radial basis function according to the experimental
data. After that, a multi-objective optimization problem (MOP) of the bus body is formulated in which the objective is to
minimize the weight and maximize the torsional stiffness of the bus body under the constraints of strength and rollover safety.
The MOP is solved by employing multi-objective evolutionary algorithms to obtain the Pareto optimal set. Finally, an optimal
solution of the set is chosen as the final design and compared with the original design. 相似文献
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J.-K. Shin K.-H. Lee S.-I. Song G.-J. Park 《Structural and Multidisciplinary Optimization》2002,23(4):320-327
Weight reduction for an automobile body is sought to achieve fuel efficiency and energy conservation. Recently, the UltraLight
Steel Auto Body (ULSAB) concept is suggested using a few methods. ULSAB pursues a lightweight automotive with steel structure.
Tailor welded blank (TWB) is one of the ULSAB methods and TWB can be utilized for an automobile door. Optimization technology
is applied to the inner panel of a door which is made by TWB. A design process is appropriately defined for the inner panel.
The design starts from an existing component. At first, the inner reinforcements are removed to use TWB technology. In the
conceptual design stage, topology optimization is conducted to find the distribution of the variable thickness. The number
of parts and the welding lines are determined from the topology design. In the detailed design process, size optimization
is carried out to find thickness while the stiffness constraints are satisfied. Size optimization is performed based on the
welding lines determined from topology optimization. The final parting lines are tuned by shape optimization. The results
from size optimization are considered constant in shape optimization. A commercial optimization software GENESIS is utilized
for the optimization processes.
Received November 10, 2000 相似文献
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Evolutionary structural optimization for stress minimization problems by discrete thickness design 总被引:3,自引:0,他引:3
Stress minimization is a major aspect of structural optimization in a wide range of engineering designs. This paper presents a new evolutionary criterion for the problems of variable thickness design whilst minimizing the maximum stress in a structure. On the basis of finite element analysis, a stress sensitivity number is derived to estimate the stress change in an element due to varying the thickness of other elements. Following the evolutionary optimization procedure, an optimal design with a minimum maximum stress is achieved by gradually removing material from those elements, which have the lowest stress sensitivity number or adding material onto those elements, which have the highest stress sensitivity number. The numerical examples presented in this paper demonstrate the capacity of the proposed method for solving stress minimization problems. The results based on the stress criterion are compared with traditional ones based on a stiffness criterion, and an optimization scheme based on the combination of both the stress minimization and the stiffness maximization criteria is presented. 相似文献