【摘要】 介绍了基于大质量法的谐响应有限元分析方法。通过大质量法使得在谐响应分析中能够直接施加加速度载荷。通过对FR-4印制板进行模态分析,研究了质量点的质量大小、数目以及施加的位置对结构固有频率的影响。基于大质量法和模态叠加法对印制板进行正弦扫频振动分析,并与完全分析法的计算结果进行比较,验证了大质量法的可行性和高效率。另外,分析表明是否选取质量点的刚体运动对应的模态决定了结果是绝对解,还是对质量点的相对解。更多还原

【Abstract】 The harmonic finite element analysis based on the large mass method was introduced.The acceleration loads were applied to the structures by this method. The influences of the mass,number and location of the punctual mass on the response of printed circuit board FR-4 were studied by performing modal analysis of the plate.The feasibility and efficiency of the method was verified by comparing the results of swept sine vibration analysis combining large mass method(LMM) and modal superposition method with those by full method.In addition,whether taking into account the mode related to the rigid motion of punctual mass or not would result in the relative solutions with respect to punctual mass or the absolute solutions.更多还原