基于PSO-NM两步识别法的桥梁损伤识别与数值仿真

Bridge Damage Identification and Numerical Simulation Use Two-step Method Based on PSO-NM

将粒子群算法(PSO)和Nelder-Mead优化算法(NM)相结合,在模态应变能指数(MSEBI)下提出了一种新型的两步识别法,该算法将结构损伤定位与定量分开考虑。首先,定义了模态应变能指数,以此用于粗略定位结构的损伤。第二步,通过PSO-NM算法求解结构损伤识别约束优化问题,确定结构损伤程度。数值仿真采用简支梁与两跨连续梁2种形式以评估本文所提方法的适用性。数值仿真结果表明,该方法不仅能有效定位结构损伤,还能准确识别梁式结构的损伤程度。同时,分步识别可以有效降低优化变量的维度,提高计算效率。

Particle swarm optimization(PSO)and Nelder-Mead optimization Algorithm(NM)are combined,and a new two-step identification method is proposed based on modal strain energy-based index(MSEBI),structural damage localization and quantification are considered separately in this algorithm.Firstly,a modal strain energy-based index is defined to roughly locate the damage of structures.In the second step,the PSO-NM Algorithm is used to solve the structural damage identification constrained optimization problem to determine the degree of structural damage.Two forms of simply-supported beam and two-span continuous beam are used in numerical simulation to evaluate the applicability of the proposed method.The numerical simulation results show that this method can not only locate the damage of the structure effectively,but also identify the damage degree of the beam structure accurately.Furthermore,the introduce of two-step identification effectively reduce the dimension of optimal parameter,which therefore improve calculate efficiency.