共查询到18条相似文献,搜索用时 62 毫秒
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采用ANSYS/LS-DYNA有限元分析软件数值模拟入水冲击问题,重点研究平板类结构体入水冲击数值仿真和冲击荷载作用下的结构动力响应;首先采用ANSYS前处理器建立平板和十字加筋板入水冲击数值模型,然后通过LS-DYNA求解器数值计算入水冲击的动力响应,并分析比较了各个模型计算得到的位移、等效应力、压力等变量变化,最后得出以下结论,加筋板具有吸收更多人水冲击能量的作用,且耐撞性更强,结构更偏于安全. 相似文献
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利用Arbitrary Lagrangian-Eulerian(ALE)有限元方法求解爆炸冲击过程中的流固耦合问题:采用ALE算法描述流体和炸药模型,采用Lagrangain方法描述舵结构模型,不同介质间的界面采用接触罚函数耦合算法。应用有限元软件ANSYS/LS-DYNA仿真模拟舵遭受TNT炸药爆炸冲击作用的全过程,得到舵的应力云图、位移云图,典型位置压力时间历程,加速度时间曲线等冲击响应。计算结果表明:利用A L E方法可以预估舵在水下爆炸冲击载荷作用下的损伤情况,为舵的抗冲击设计提供依据。 相似文献
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作为飞机结构的基本元素,加筋短板有较为宽广的非线性后屈曲区间.通常采用工程计算方法作为加筋板的设计依据,未充分利用结构的后屈曲强度.为研究加筋短板的后屈曲特性,求解加筋短板的后屈曲路径以及极限载荷,采用GMNIA(Geometrically and material nonlinear analysis with imperfections)仿真分析方法预测了加筋短板的极限载荷,得到了反映后屈曲路径的载荷—应变曲线,并与试验进行对比分析.研究结果表明,加筋短板初始屈曲发生在蒙皮的自由边,长桁是后屈曲的主要承载部位;有限元仿真的极限载荷与试验破坏载荷的相对误差为0.46%,有限元仿真的后屈曲平衡路径与试验吻合较好.因此,采用GMNIA仿真分析方法能够准确的分析加筋短板的后屈曲特性,达到减轻结构重量、提高结构效率的目的. 相似文献
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为使金属加筋板稳定性分析更加真实可靠,在分析中引入随机的初始几何缺陷,采用一致缺陷法通过ANSYS对金属加筋板进行压缩稳定性有限元分析,总结一致缺陷法的优缺点,进而提出一种考虑加筋板初始几何缺陷的随机缺陷法并进行试验.结果表明:一致缺陷法对非线性变形分析有一定的引导作用,使非线性变形朝着特征值屈曲模态的方向发展;随机缺陷法将结构的初始缺陷看作是随机的,缺陷大小和分布无法预测,更能反映加筋板真实的工作性能.编写加筋板自动建模程序和随机缺陷自动分析程序,从而大大提高分析效率,使随机缺陷法用于设计成为可能. 相似文献
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薄板在爆炸冲击载荷作用下的动力行为复杂,具有大变形、瞬时性、高度非线性等特点.当冲击波冲量较小时,薄板容易发生异常动力响应.然而,爆炸冲击波特征对薄板异常动力响应的影响尚不明晰.为此,本文采用经实验数据验证的自主开发爆炸载荷模型,首先成功地模拟了方形薄板的反直观异常动力响应;然后通过数值仿真研究了冲击波负压描述方法、正压衰减系数等对薄板异常动力响应的影响;最后,发现了在距离当量比一定时,随着爆炸距离的增加薄板依次发生继发直观、反直观、混合、始发直观四种行为模式,并分析了不同行为模式下响应历程与塑性耗散能之间的关系. 相似文献
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采用试验和有限元方法研究复合材料板 铝合金板单搭接接头在热和力载荷共同作用下的钉载分配和钉孔周边应力分布。将仿真模型得到的钉载分配结果与试验结果进行对比发现:温度升高后,靠近加载端承载最大的螺栓载荷分配比例增大,相应位置钉孔周边应力水平也有较大幅度的增加。对比未考虑热残余应力模型发现:考虑热残余应力模型与试验结果最相近;同样温度时热残余应力的存在使应力水平提高10%左右,说明在热载荷作用下考虑热残余应力的必要性。复合材料与金属接头钉孔周边应力分布呈“枫叶”状。 相似文献
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为改善在计算板的几何非线性问题时有限元法系统过硬的数值缺陷,提高计算精度,在考虑剪切变形的yon Karman假设下,基于全拉格朗日描述方法,将边光滑有限元法应用于板的几何非线性分析.计算公式基于1阶剪切变形理论,并采用离散剪切间隙有效地消除剪切自锁.在三角形单元的基础上进一步形成边界光滑域,在每个光滑域内对应变进行光... 相似文献
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为设计更薄的热风炉热风竖管底板,解决试验结果和经验公式计算结果无法反映其实际受力情况的问题,用ANSYS分析某底板的结构强度.根据该底板的结构几何模型建立有限元模型,采用SOLID 185单元划分网格.分析中不考虑固定支座处的滑动;设定砖载荷、上部竖管自重载荷、内压载荷、温度载荷等边界条件.对底板、底板下部筋板、筒体和筒体外围筋板的应力与位移分布的分析表明:底板及其筋板与竖管筒体连接处易出现应力集中现象;在热膨胀和内压的作用下,最大位移出现在底板下部筋板与筒体交界处、筒体自由边界处和筒体外围筋板的上部.计算结果表明该底板能满足结构强度要求. 相似文献
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利用MSC.Patran和MSC.Nastran进行浮筏系统的冲击动响应分析计算是一项烦琐而复杂的过程,定制开发浮筏冲击动响应分析计算系统具有重要的应用价值.描述了系统的设计框架及功能模块,介绍了系统的具体实现及工作流程.为了充分利用已有的数据资源,系统中实现了MSC.Patran与已有浮筏数据库系统的交互.通过一个工程示例,说明了系统的有效性. 相似文献
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The dynamic failure of Au RF-MEMS was investigated over a wide range of loading rates by three different experimental setups: a drop weight tower, which induced a maximum peak acceleration of 600g (g: acceleration of gravity), a Hopkinson pressure bar with a maximum peak acceleration of 300,000g, and a pulsed laser loading technique with a maximum peak acceleration of 1.8 × 108g. In the drop weight tower the total load pulse duration was in the milliseconds range – much longer than the 28 μs resonant period of the devices – and no failure of any kind occurred in the RF-MEMS devices or their substrate. At 90,000g (generated in the Hopkinson bar) no damage in either the substrate or the devices was observed. However, at 200,000g, which corresponds to a loading duration of a few microseconds, i.e., comparable to the device resonant period, 10% of the switches failed although postmortem imaging showed no damage to the substrate. Damage increased after this acceleration and at 300,000g 20% of the switches failed, but, in addition, significant failure in the quartz substrate was recorded. Lastly, the pulsed laser loading technique, which has a loading pulse duration of a few tens of nanoseconds, was applied to accelerate the Au switches to 1.8 × 108g, and the probability of failure at this loading ranged from 50% to 80%. At even larger accelerations, 109g, the probability of failure was 100%. The results of this study establish the severity of dynamic failure in MEMS, despite their small mass, and its dependence on the level of acceleration which spanned about 7 orders of magnitude. 相似文献
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《Ergonomics》2012,55(10):1503-1514
The primary objective of this paper was to compare in-shoe loading for different models of running shoe using measurements of force distribution. It was hypothesised that a shoe designed with minimal focus on cushioning would demonstrate significantly higher peak forces and rates of loading than running shoes designed with cushioning midsoles. Loading was compared using in-shoe peak forces for six footwear conditions. It was found that peak rate of loading at the heel provided clear distinctions between shoes. In support of the study hypothesis, the shoe with minimal focus on cushioning had a significantly higher rate of loading than all but one of the other test shoes. Data collected for midfoot and forefoot areas of the foot highlighted the importance of considering loading across the foot surface. The results of the present study demonstrate that pressure insoles provide a useful tool for the assessment of loading across the foot plantar surface for different footwear conditions. There are numerous models of running shoe for individuals to select from, with limited information available regarding the performance of the shoes during running. The current study demonstrates differences in loads across the foot plantar surface during running, indicating differences in performance for different footwear models. 相似文献