摘要
以某直立四缸柴油机为例 ,用 Pro/ Engineer软件在建立底部被约束的机体三维实体模型的基础上 ,对机体结构进行了约束模态的有限元分析 ,得出了机体结构的前 2 0阶约束模态的固有频率及相应振型 ,并与机体自由模态分析结果进行了比较。结果显示出了机体各部分结构振动的强弱分布以及抗振薄弱区 ,揭示了不同频率范围内机体结构振动模态的特点。同时 ,分析结果表明 :约束模态的固有频率及振型都与自由模态有显著的差别 ,因此考虑约束边界条件的机体模态分析对揭示机体结构的动力学特性是非常有必要的。
The three dimensional model of a in line four cylinder diesel engine block with constraint at the bottom is established with the Pro/Engineer software,and then the modal analysis of the engine block is carried out using finite element method in the case of constrained model.Through the analysis,the inherent frequencies and mode shapes of the first 20 order modes are obtained respectively,and then are contrasted with the results of free modal analysis accomplished previously.The results show the relative distribution of the vibration magnitude in the whole block and reveals the characteristics of modes in various frequency bands.Meanwhile,it is concluded that not only the natural frequencies but also the mode shapes are remarkably different from that of free modes.So it is very necessary to carry out constrained modal analysis for revealing the dynamic characteristics of engine block.
出处
《内燃机学报》
EI
CAS
CSCD
北大核心
2002年第1期75-78,共4页
Transactions of Csice
基金
国家自然科学基金重大资助项目 (59990 4 70 )
