基于应变测试矿用汽车车架结构优化设计分析

Structural Optimization Design and Analysis of Mining Truck Frame Based on Strain Test

矿用铰接车采用液压举升机构实现货物卸载,受力情况复杂,对车架结构影响大且要求高。针对某自卸车后车架和货箱在不同运行条件下的承载特性进行分析,获取各工况的载荷情况和边界条件;根据前述分析,建立后车架和货箱的有限元分析模型,选取多个典型工况开展分析,获取应力应变的分布情况;采用材料升级、圆角优化及焊接工艺提升等,针对应力集中和较大位置进行优化设计,降低应力值,保证安全裕度满足要求;采用直角应变测试法,针对实际自卸车车架开展应力测试,在分析的关键位置布置应变片,选取典型工况开展测试,并与仿真结果开展对比。结果可知:自卸车铰接点和液压举升缸鹅颈支撑处应力较大,并且出现了应力集中,但均在许可范围之内;采用厚度提升、直径增大及焊接工艺提升等方法,有效提升应力分布,最大值明显降低;实车测试和仿真分析,满载工况应力分布基本一致,最大值误差低于5.8%;优化后结果明显低于优化前;结果表明分析模型和优化方法的可靠性,为此类分析设计提供参考。

The hydraulic lifting mechanism is adopted for the articulated mining truck to realize the unloading of goods.The stress condition is complex,which has a great impact on the frame structure and high requirements.The load characteristics of the rear frame and container of a dump truck under different operating conditions were analyzed,and the load conditions and bound-ary conditions under various working conditions were obtained.According to the above analysis,the finite element analysis model of the rear frame and container was established,and several typical working conditions were selected for analysis to obtain the dis-tribution of stress and strain.Through the use of material upgrading,fillet optimization and welding process improvement,the op-timization design was carried out for the stress concentration and large position,so as to reduce the stress value and ensure that the safety margin meets the requirements.Based on the right angle strain test method,the stress test was carried out for the actual dump truck frame,the strain gauge was arranged at the key position of the analysis,and the typical working conditions were se-lected for the test,and compared with the simulation results.The results show that:the stress at the hinge joint of dump truck and the gooseneck support of hydraulic lifting cylinder is large,and the stress concentration appears,but they are all within the allow-able range.The stress distribution is effectively improved and the maximum value is significantly reduced by means of thickness in-crease,diameter increase and welding process increase.According to the real vehicle test and simulation analysis,the stress distri-bution under full load condition is basically the same,and the maximum error is less than 5.8%.The results after optimization are significantly lower than those before optimization.The results show the reliability of the analysis model and optimization method,and provide a reference for such analysis and design.