ժҪ ��ĳ�ͺ���½������½����Ϊ�о�����,����MSC.Patran/Nastran ������½��������ģ̬����,�õ��ṹģ̬����ҪӰ������,��Ҫ���������ߴ��װ�����ӷ�ʽ.��Ҫ����������½��������֧��������֧�������˺ͻ���Ͳ�ں��Լ�����Ͳ�˸Ǻ�ȶ�ģ̬Ƶ�ʵ�Ӱ��,������֧��������֧�������˺ͻ���Ͳװ�����ӷ�ʽ�����о�,�������һ�ֻ���Bush��Ԫ��װ�����ӷ�ʽ,��Ч�ؽ���˴�ͳ��������MPC(Multiple Point Constraint)����������ģ��װ�����ӵĲ���,ʹ����������ȷ.������£״̬�µ�ģ�ͽ�����Ƶ����Ӧ����,��������ڸ�����Ƶ�ʷ�Χ�ڽṹ���ᷢ������,��һ��˵���ṹ��Ƶĺ�����.
By the modal analysis of lunar lander based on MSC.Patran/Nastran, the main factors affecting the mode frequency were retrieved, including the dimensions of the machine and the method of the assembled part. The influence brought about by modifying the thickness of the piston barrel and piston rod on the mode frequency was illustrated. Meanwhile, the connection method of the assembled part was also studied. Subsequently a new approach based on Bush was proposed to solve the problems encountered by using MPC(multiple point constraint), which makes the simulated results more accurate. Finally, frequency analysis on the stow model of the lunar lander was implemented, whose result shows the structure can not resonated in the specified range of excitation, which further validates the reliability of the lunar lander.