载荷识别方法是工程振动噪声测试与分析中常用的一种振动响应逆向求解方法。但是由于载荷识别方法实施的过程中不能很好地考虑结构系统的复杂阻尼特性,导致在离激励点较远的远场,误差非常大,这对载荷识别方法的广泛应用提出了挑战。提出虚拟远场激励方法,即在离激励点较远的远场位置布置虚拟激励点,来实施载荷识别,由此可以避免结构中由于离激励点较远的位置的存在而带来的远场求解误差。通过与试验测试数据、传统载荷识别方法求解结果进行对比,表明采用虚拟远场激励方法求解得到的振动响应与试验测试数据更为接近,特别是在远场,误差得到了显著的改善。这表明,虚拟远场激励方法可以有效提高传统载荷识别方法在远场的求解误差,而且可以广泛用于各种载荷激励难以确定的复杂机械系统的振动求解。
The load identification method is a commonly method for the vibration response reverse solving in engineering vibration and noise testing and analyze. However, due to the load identification method cannot be well to consider the complexity damping characteristics of the system when the method is carry out, the errors in the far-field away from the excitation point field is very large, so the load identification method is facing the widely challenges. A virtual far-field excitation method is proposed, in which the virtual excitation point is arranged farther away from the excitation point position of the far-field to carry out the load identification solving. It can avoid the solver error caused by the distance between the excitation point and response points. After comparing with the experimental test data and the results solved by load identification method, suggests that the results solved by virtual far-field exciting method are more closely with the test data, particularly in the far field, the errors have been significantly improved. This indicates that the virtual far-field excitation method can effectively improve the solving the error in the far field of the traditional load identification method, and can be widely used to solve the vibration of complex mechanical system, in which the load excitation is difficult to determine.