激光冲击适张圆锯片振动模态的理论分析

Theoretical analysis for vibration mode of laser shock tensioned circular saw blade

为了能兼顾计算效率与精度,基于非线性有限元理论,进行合理简化与假设,提出利用弹性热膨胀等效替代冲击区域塑性变形的方法,基于ABAQUS非线性有限元软件建立了集弹塑性和振动模态分析于一体的圆锯片激光冲击适张理论分析模型,获得圆锯片激光冲击适张后适张应力场和固有频率的仿真计算结果。利用静态应变采集仪和电阻应变花,测试圆锯片激光冲击适张后生成的适张应力场。通过与实测适张应力进行对比,验证了理论分析模型的正确性。理论计算结果表明:激光冲击适张能够使圆锯片外缘生成切向拉应力,提高圆锯片Nc=0,Nd≥2振动模态所对应的固有频率,可以有效提高圆锯片的动态稳定性。

To give consideration to both computational efficiency and accuracy,based on nonlinear finite element theory,with reasonable simplification and assumption,a method using elastic thermal expansion instead of plastic deformation in shock zone was proposed,and a theoretical analysis model of laser shock of circular saw blade was established by ABAQUS software,which combined elasto-plastic and vibration mode analysis.Tensioning stress and natural frequency of circular saw blade after laser shock tensioning process were calculated by this model.Tensioning stress of circular saw blade after laser shock tensioning process was tested by static strain gauge and resistance strain acquisition.By comparing theoretical analysis and measured results of tensioning stress,the correction of the theoretical model was proved.The theoretical results show that tangential tensile stress is produced in the outer edge of circular saw blade after laser shock tensioning process,and the natural frequencies of mode Nc=0,Nd≥2 of circular saw blade increase and the dynamic stability of circular saw blade is improved effectively.