共查询到18条相似文献,搜索用时 796 毫秒
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基于Plackett-Burman多因素筛选设计方法确定响应面的待定系数,分析影响路面结构设计指标的关键因素,用最陡爬坡试验逼近关键因素的最大响应区域,应用响应面法以费用最低、弯沉和设计层层底最大拉应力最接近设计值为目标对路面结构各个参数进行优化,得到各路面结构参数的最佳取值。通过该方法与其他路面结构设计方法的特点综合比较,可知,响应面设计方法可在保证结构可靠性前提下实现对费用的优化,并且可操作性较遗传算法和均匀设计法简便。 相似文献
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为提高大跨钢箱梁斜拉桥的施工控制精度,以某大跨斜拉桥为研究对象建立有限元模型,分析拉索弹性模量、主梁弹性模量、主梁体积重量、桥塔刚度等主要结构参数变化对结构响应的影响,以成桥线形、拉索索力、主梁应力、索塔应力、桥塔偏位为控制目标进行结构参数敏感性分析。结果表明,拉索弹性模量对成桥主梁线形、拉索索力影响较大,为敏感性参数;主梁线形、拉索索力、桥塔偏位对结构参数的变化较敏感;中跨主梁线形比边跨主梁线形对参数变化更敏感;主梁应力对拉索弹性模量减小较敏感;桥塔应力对主梁体积重量减少较敏感。 相似文献
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为确保猛洞河大桥施工过程的安全、设计目标的实现、施工工序的简化,研究其拱圈施工的斜拉扣挂方案.基于考虑施工过程的平面杆系有限元法,以拱肋线形偏差(拱肋制作线形与拱肋合龙设计线形的偏差)等于0为目标,并令交于索塔同一高度处的扣、锚索水平分力相等,采用正装迭代法确定劲性骨架安装阶段的扣锚索张拉力;以拱圈应力满足规范要求为条件,用试算法确定主拱圈外包混凝土浇注过程的扣索索力初张值和调整值.在上述方案基础上,对骨架安装和外包混凝土浇注两个关键施工阶段分别进行关于拱肋线形和应力的参数敏感性分析,找出了灵敏度较大的结构参数,以便进行有针对性的控制.利用外包混凝土合龙状态的参数敏感性分析结果,对外包混凝土浇注过程中的扣索布置方案和完成后的拆除顺序进行了优化. 相似文献
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在铸件设计时一般都是先经过拓扑优化然后再进行结构设计,但拓扑优化无法得到确定结构的最优尺寸,仅能得到给定边界条件下的基本形式,因此在拓扑优化后如何进行详细尺寸设计对设计者要求较高,有时会设计出很多方案进行强度验证,且这些方案往往不是最优方案。在拓扑优化分析完毕后再加入灵敏度优化技术,可以快速得到满足设计要求且重量最轻结构的详细尺寸,大大提高了设计效率。 相似文献
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为优化推力杆的球铰结构并提高其疲劳寿命,提出一种基于有限元法和遗传算法的推力杆球铰多目标优化方法。该优化方法通过有限元法计算不同橡胶衬套预压缩量和球铰结构的推力杆球铰橡胶衬套的应变分布特征和刚度参数,进而得到推力杆刚度参数、橡胶衬套预压缩量与球铰关键结构参数之间的关系,并在此基础上采用遗传算法建立推力杆球铰的多目标优化模型。利用建立的多目标优化模型计算得到推力杆球铰的优化方案。样件台架试验结果表明,此优化方案使推力杆球铰的疲劳寿命提高了7倍。提出的多目标优化方法充实了变截面橡胶金属复合结构的设计理论,并为推力杆的优化设计提供了理论依据。 相似文献
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以某特大桥桥墩混凝土施工中钢模板设计为背景,结合Midas Civil有限元分析软件建模仿真分析该钢模板在混凝土侧压力作用下的各构件受力,通过改变对拉杆刚度、对拉杆位置来确定钢模板整体结构的最优受力,结果表明:在一定的对拉杆刚度情况下,合理的对拉杆位置对结构整体受力有着很大的提升;增加对拉杆刚度可以加强结构受力,但该过程不是无止境的增加,而是非线性的,增加到一定刚度情况下结构受力达到一个相对稳固状态;同时提出一些在钢模板设计和检算中的主要问题并提出改善建议。 相似文献
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J. K. Kim Y. J. Kim W. H. Yang Y. C. Park K.-H. Lee 《International Journal of Automotive Technology》2011,12(3):375-381
This study proposes a structural design method for an outer tie rod installed in a passenger car. The weight of the outer
tie rod is optimized by using the aluminum alloy Al6082M, which is developed as a steel-substitute material, and applying
structural optimization techniques. The high strength aluminum with improved mechanical properties was developed to reduce
the weight of the outer tie rod. The newly developed aluminum alloy Al6082M is applied as the material of the outer tie rod.
The static strength due to inertia force, durability and buckling performances are considered in the structural design of
the outer tie rod. At the proto design stage of a new outer tie rod, it is cost-effective to utilize FE (finite element) analysis
to predict each of these performances. In addition, the current trend in the structural design of automobile parts is to use
optimization techniques to reduce the weights of the parts. First, for an arbitrary base design, the static strength, the
life cycle and the buckling load are calculated to check whether the design satisfies its criteria. Then, the critical performance
is selected so as to include its loading condition only in the optimization process. In this study, the metamodel based optimization
process using kriging is adopted to obtain the minimum weight satisfying the critical design requirement. Then, the feasibility
of the determined optimum shape is investigated against the other performances. Finally, the optimum design of outer tie rod
is modified by considering forging efficiency. The performances of the final design are investigated through simulation and
experiment. 相似文献
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对一座长联大跨连续梁桥进行数值模拟分析,利用通用有限元软件Midas Civil建立有限元模型,对长联大跨连续梁结构在施工过程中的关键阶段进行应力和位移分析,并得出重要结论.同时对影响桥梁受力状态的各参数进行敏感性分析,并指出预应力、弹性模量、容重是影响桥梁状态的主要参数,而混凝土徐变是不可忽视的重要参数.分析方法和部分结论对同类桥梁的设计和施工具有一定的指导意义. 相似文献
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At conceptual design stage, beam element is extensively used to create the frame structure of automobile body, which can not only archive the accurate stiffness but also reduce much computational cost. However, the stress definition of beam element is very complex so that the stress sensitivity and optimization are difficult to analytically derive and numerically program. This paper presents an solution to this problem and an application in the lightweight optimization design of automobile frame. Firstly, maximal Von Mises stress of rectangular tube is calculated by using the superposition of stress, which is together induced by the axial force, bending moments, torsional moment and shear force. Secondly, the sensitivity of Von Mises Stress with respect to size design variables: breadth, height and thickness are derived, respectively. Thirdly, an optimal criterion is constructed by Lagrangian multiplier method to solve the frame optimization with stress constraints. Lastly, numerical example of car frame proves that the proposed method can guarantee the stress of each beam element almost fully reaches at the yielding stress. 相似文献