基于功率谱密度工程车辆驾驶室随机振动分析

Analysis of the Cab’s Random Vibration of Construction Vehicle Based on Power Spectral Density

路面随机振动激励对驾驶室结构具有一定的疲劳破坏作用,对驾驶室进行随机振动分析,可以分析随机振动载荷对驾驶室结构的影响。根据驾驶室受到的随机振动冲击情况,基于ANSYS驾驶室有限元模型,获得驾驶室的固有振动模态;并根据工程车辆的实际运行状况,选取空载30km/h、空载40km/h、重载20km/h和重载30km/h等四个主要工况进行随机振动分析。通过对驾驶室结构的ANSYS动力学仿真分析发现,结构最大应力产生在空载40km/h工况下,位置发生在上顶板与上斜梁的连接处。以此结果作为疲劳分析的前提,根据Q235钢的S-N曲线和疲劳累积损伤理论,利用Steinberg三区间法对驾驶室结构进行疲劳强度分析,结果可知,驾驶室结构的累积疲劳损伤度远远小于1,说明驾驶室结构满足疲劳强度要求,为此类设计研究提供参考。

The random vibration excitation of road surface has certain fatigue destructive effect on the cab structure.Random vibration analysis of the cab can be used to analyze the effect of random vibration loading on the cab structure.According to the impact of the random vibration of the cab,based on the finite element model of ANSYS,the natural vibration mode of the cab was obtained.According to the actual operation of the vehicle,there are four main working conditions,which were running at the speed of 30km/h unloaded,40km/h unloaded,20km/h fully loaded and 30km/h fully loaded,random vibration analysis of the cab was analyzed.As a result,when the damp truck runs at the speed of 40km/h unloaded,the maximal stress was on the top cover join with the top diagonal beam,which was the biggest of all the working conditions.Based on the S-N curve and fatigue cumulative damage theory of Q235 steel,the fatigue strength of the cab structure was analyzed by Steinberg three-interval method.The results show that the degree of the cumulative fatigue damage is much smaller than one,so the structure is impossible to fatigue.