基于Nastran的汽车仪表管梁模态分析与优化

Modal Analysis and Optimization of a Car Cross Beam Based on Nastran

针对某型汽车的仪表管梁展开计算模态分析与优化。网格划分关注了材料属性、网格质量、焊点设定以及约束状态,提高了仿真计算的精准性。通过Nastran计算得到管梁的前十阶模态,其中全局弯曲模态频率与汽车怠速频率非常接近,影响振动性能。对管梁进行灵敏度分析后找到关键部件,并利用优化算法得到最佳设计参数。优化后的管梁全局模态频率得到提高,避免了怠速共振。模态试验验证了共振性能的提升和有限元仿真分析与优化的准确性。

Computational modal analysis and optimization of a car cross beam （CCB） are carried out. Meshing concerns material property,mesh quality,welding spot setting and constraint which improve the accuracy of simulation. The first ten modes of CCB are obtained by calculation with Nastran. The result shows that global bending modal frequency is very close to vehicle idle frequency,which affects the vibration performance. After a sensitivity analysis of CCB,the key components are found and the optimum design parameters are obtained by using the optimization algorithm. The global modal frequency of the optimized CCB is improved and the idle resonance is avoided. A modal test proves the improvement of resonance performance and the accuracy of simulation analysis and optimization.