工程车辆翻车时ROPS刚度、斜坡角度和安全带方式对人体损伤的影响

应用有限元与多刚体方法,针对某ZL50型装载机沿30°和45°斜坡翻车过程中司机动态响应进行仿真分析。以人体损伤为评价指标对比分析了不同的翻车保护结构(ROPS)刚度、斜坡角度以及安全带约束方式对司机损伤的影响。结果表明:在能够提供人体生存空间的前提下,ROPS刚度越小,人体受到的损伤越小;斜坡角度的变化影响人体损伤部位;4点式安全带能够有效降低人体头部损伤的几率;安全带形式对颈部损伤影响很小。     

ZL80G装载机倾翻保护结构侧向加载塑性极限特性

研制了ZL80G装载机的安全驾驶室式倾翻保护结构,给出了整车级别的倾翻保护结构侧向加载塑性极限特性的数值模拟方法和试验方法,并进行了计算机仿真与样机试验,进一步研究了侧向变形机理、承载规律和能量吸收规律。结果表明:仿真结果与试验结果一致,塑性铰先后出现在下、上横梁两端的设计位置,侧向塑性极限承载能力是标准值的1.27倍,倾翻保护结构屈服后吸收了72.1%的翻车冲击能量,侧向承载与能量吸收匹配得较好;ZL80G的倾翻保护结构满足ISO3471侧向加载要求。     

滑移装载机翻车保护结构性能仿真与验证

针对滑移装载机驾驶室翻车保护结构(ROPS)的破坏性试验费用高、进度慢的问题,提出使用ANSYS非线性有限元分析法,依据ISO3471标准对ROPS性能试验进行模拟仿真,将仿真数据与试验结果进行对比分析,验证了仿真方法的有效性。     

振动压路机安全驾驶室ROPS侧向加载特性研究

针对某振动压路机安全驾驶室ROPS侧向加载工况,利用非线性有限元法建立了ROPS有限元模型,分析了ROPS在此工况中的侧向力、侧向位移、侧向能量吸收能力三者间的规律,讨论了侧向承载能力与侧向能量吸收能力的关系。结果表明:侧向承载能力在弹性变形阶段达到标准的要求,侧向吸能在塑性机构变形阶段才达到要求;在许可的载荷区内,侧向力作用位置不同,侧向力曲线和侧向吸能曲线也不同。     

矿用自卸车ROPS结构研究

本文以某矿用自卸车为研究对象,类比设计一种集成式ROPS结构,并基于ANSYS软件依据标准ISO 3471-2008进行加载分析。通过对加载过程中ROPS结构变形量的分析,判断ROPS结构是否能满足标准规定的性能要求。分析结果显示,在侧向、垂直、纵向加载过程中,ROPS部件没有任何部分侵入DLV界面,表明在车辆发生倾翻事故时该ROPS结构可以对驾驶员起到有效保护作用。     

工程车辆ROPS动态仿真与试验研究

提出了基于整车的ROPS动态仿真建模方法和滚翻试验方法;以轮式装载机模型在倾角为30°的硬斜坡滚翻工况为例,进行了ROPS仿真结果和试验结果对比,验证了建模方法的合理性;揭示了碰撞过程中ROPS的冲击力、变形和能量吸收规律。     

矿用自卸车ROPS的有限元分析和结构改进

以某168 t矿用自卸车为例,结合承载能力和自身轻量化的要求,建立翻车保护结构的有限元模型,根据国际标准的要求进行仿真,并提出了2个改进模型的方案,使分析结果达到翻车保护结构在满足性能要求的前提下轻量化。     

重载矿用自卸车驾驶室ROPS&FOPS有限元分析

根据最新国际标准,运用大型通用有限元软件ANSYS Workbench,对重载矿用自卸车驾驶室ROPS&FOPS进行落锤冲击试验模拟与侧向、竖向、纵向载荷的加载试验分析,结果表明:该结构变形未侵入DLV,能量吸收性能满足标准要求。     

翻车保护结构安全性能动态试验的数值仿真

为完善有限元方法在翻车保护结构(ROPS)静/动态强度仿真试验中的应用,同时能在设计阶段充分考察ROPS的安全性能,使之顺利通过相关法规的检测,以某型号拖拉机ROPS为研究对象,根据OECD标准Code-3中关于对ROPS强度试验的要求,对模型进行合理的简化,首次提出利用有限元软件ABAQUS/Explicit对ROPS后撞试验过程进行仿真.结果显示ROPS的部分区域已经发生塑性变形,最大变形发生在撞击点处,但没有侵入安全容身区,符合标准的验收条件.各部分的应力分布与实际后翻事故中拖拉机受到冲击载荷作用的受力状况较为吻合,可以作为结构改进的依据.提出的仿真方法能有效地模拟撞击试验的动态过程,可为类似工程结构的动态仿真分析提供一定的参考.     

Multiaxial softening hinge model for tubular vehicle roll-over protective structures

The purpose of the work described in this paper is to provide a computational tool for the design of roll-over protective structures (ROPS) comprised of thin-walled rectangular tubes. This tool simulates the multi-stage, regulatory quasi-static loading test (SAE Standard, SAE J1040 APR88) that new designs must pass. These tests are claimed to be indications of the performance of a ROPS under real (dynamic) roll-over conditions. The collapse of the framework involves large, three-dimensional deformation, which results mainly from large rotations in each member due to bending and torsion. To establish constitutive relationships for a framework model, biaxial bending collapse behaviour of thin-walled rectangular tubes was investigated using a kinematic approach to generate the bending interaction curves. The interaction between bending and torsion was examined separately using extensive finite element analyses of cantilevers modelled by the commercial finite element code ABAQUS. Approximate constitutive relationships were then formulated for a ‘hinge super-element’ to be implemented via the user-defined element subroutine UEL in ABAQUS. The hinge element consists of two nodes separated by a small distance. Each node has six degrees of freedom and the components of stiffness at each node are initially set to sufficiently large values to provide rigid response in the pre-collapse stage. When the collapse criterion is satisfied for the first time, the hinge element is switched to ‘softening’ hinge response and thereafter follows the local softening behaviour of a closed-section tube by modifying the stiffness of the three rotational components according to the constitutive relationships. To test the validity of the hinge model, the response of a simple, scaled ROPS to a simulated prescribed regulatory test load history (SAE Standard) was compared with the results from the analysis of an equivalent shell element model. Good agreement is demonstrated between the two models.