为提高液压挖掘机工作装置动态性能的优化效率，在对该结构进行试验模态研究的基础上，用双模态空间动力修改方法进行了动力特性修改研究，研究结果表明：质量修改对该结构的1阶、2阶固有频率和阻尼比有显著影响，对其他阶结构动态特性的影响很小；刚度修改对该结构1阶至5阶的固有频率和阻尼比均有明显影响，高阶的固有频率和阻尼比对刚度的变化敏感。所得到的结论揭示了模态参数调整对液压挖掘机工作装置动力特性的影响规律，为提高机械产品的总体质量奠定了基础。

To improve dynamic performance’s optimization efficiency of hydraulic excavator’s work device, the dynamic modification simulation of the structure was investigated by dual modal space method based on modal analysis. The results show that the mass modification remarkably influences the first and second order natural frequency and damp ratio, and has little effect on high order modal frequency and damp ratio. The stiffness modification influences the first five modal frequency and damp ratio remarkably; high order modal frequency and damp ratio are sensitive to stiffness modification. The investigating results reveal the relationship between modal parameter modification and dynamic characteristic of the structure, and lay the foundation for improving overall quality of mechanical products.