天然气牵引车车架轻量化研究

Research on Lightweight of CNG Tractor's Frame

建立了某公司生产的天然气牵引车车架有限元模型,通过静动态分析得到了车架的刚度和典型工况下的强度及车架前4阶振动的固有频率和振型。以刚度最大为目标以体积分数为约束,应用基于OptiStruct的拓扑优化技术获得了弯曲、纯扭转和弯扭组合工况的拓扑优化材料分布图。根据拓扑优化结果对该车架进行二次设计,将鞍座前横梁改进为抗扭能力更强的新型横梁并在纵梁内侧前吊耳处加装一对衬板以提高局部刚度。对改进后车架结构进行尺寸优化以确定车架各结构最佳板厚。分析结果表明:最终优化得到的车架综合性能优于原车架,并实现了减重13.82%。

Based on the frame of a CNG tractor, the finite element model was established by HyperMesh. The stiffness, strength of typical working conditions and the first four orders natural frequency and vibration mode of vibration were gained through static and dynamic analysis. Regarding the maximum stiffness as the aim and the volume fraction as the constraints, the drawing of material distribution of topology optimization in the bending, torsion and combined bending with torsion condition was got by the technology of topology optimization based on OptiStruct. In accordance with the result of the topology optimization, the frame was redesigned and new model was obtained. The beam in front of the saddle was replaced by a new one whose anti-torsion ability was better and a couple of lining boards were added to the inside of the certain edge beam at the point of front lifting lug in order to improve the local stiffness. The appropriate thickness of the new frame was confirmed by size optimization. The analysis shows that the overall performance of the new frame is better than before, besides the weight is reduced by 13.82%.