Because of high sharp peak , vibration stress is big , and the maximum stress achieves 550mpa 由于油缸冲击载荷有比较大的峰值，泵车动应力比较大，最大值达到550mpa 。
The effect that brunt load act on the arm frame of the bump auto is discussed by way of dynamic response analysis 通过动态响应分析，讨论了工作冲击载荷对泵车臂架振动的影响。
Set up concrete pump car arm shelf mechanics and finite element model of structure , and has carried on the experiment to verify 第4章建立了混凝土泵车臂架结构的力学和有限元模型，并进行了实验验证。
3 inherent vibration frequency and relative vibration shape of the bump auto working under various condition can be received from mode analysis 3 、模态分析得到该泵车不同工况下的固有频率和相应的振型。
Three structural fe model are established with the fem based on msc / nastran . in the first optimization model , the exhaustive parameters are selected firstly 进一步利用有限元分析软件msc nastran建立了三个水泥输送泵车结构有限元优化模型。
4 circulation brunt load acting on given finite element modules , time domain strength analysis and frequency domain strength analysis are performed 4 、在有限元模型上施加试验得到的油缸循环冲击载荷，对该泵车进行时域动强度分析和频域动强度分析。
The stress of horizontal working states is bigger than others , and the maximum stress attaches to 540 mpa . only considering static strength , the bump auto satisfies command 水平工况应力较大，最大应力为540mpa ，单从静强度方面考虑，该泵车满足强度要求。
Vibration equipment : two vibrators per pump truck , two vibrating head , two vibrator for standby , four vibrating head , total ten vibrator and twelve vibrating head 4振动机具：每台泵车2台振动器、 2根振动棒，另备用2台振动器、 4根振动棒，共10台振动器、 12根振动棒。
In the second optimization model , the first mode frequency is decreased to let it below the frequency of brunt load and cut down greatly the structural mass 在第二个优化模型中，考虑减小泵车的一阶频率，尽量低于油缸冲击载荷的频率，同时可使结构质量有较大幅度下降。
