In this paper,we propose a three-term conjugate gradient method for solving unconstrained optimization problems based on the Hestenes-Stiefel(HS)conjugate gradient method and Polak-Ribiere-Polyak(PRP)conjugate gradien...In this paper,we propose a three-term conjugate gradient method for solving unconstrained optimization problems based on the Hestenes-Stiefel(HS)conjugate gradient method and Polak-Ribiere-Polyak(PRP)conjugate gradient method.Under the condition of standard Wolfe line search,the proposed search direction is the descent direction.For general nonlinear functions,the method is globally convergent.Finally,numerical results show that the proposed method is efficient.展开更多
桥梁车辆移动载荷识别MFI(Moving Force Identification)是结构动力学领域中的一个典型反问题.针对现有基于共轭梯度方法的载荷识别方法对多轴车辆荷载识别效果不佳的问题,提出了一种基于改进分数阶共轭梯度算法IFCG(Improved Fractiona...桥梁车辆移动载荷识别MFI(Moving Force Identification)是结构动力学领域中的一个典型反问题.针对现有基于共轭梯度方法的载荷识别方法对多轴车辆荷载识别效果不佳的问题,提出了一种基于改进分数阶共轭梯度算法IFCG(Improved Fractional Conjugate Gradient)的载荷识别方法.基于车辆行驶过程在时域中建立车桥动力系统,通过模态叠加原理得到桥梁动态响应,将MFI问题转化为无约束优化问题;其次,引入新的搜索方向标量,使所提算法能够针对多轴以及高噪声情况下保持精度和识别效率;接着,通过识别两轴车辆移动载荷验证了所提方法的有效性;然后,对分数阶次进行定量对比研究,选择最优分数阶次;最后,通过识别多种工况下的三轴车辆载荷,将所提方法与现有方法进行对比,验证了IFCG方法在不同工况下的桥梁多轴车辆MFI都具有较高的识别精度和速度.展开更多
基金Supported by the Science and Technology Project of Guangxi(Guike AD23023002)。
文摘In this paper,we propose a three-term conjugate gradient method for solving unconstrained optimization problems based on the Hestenes-Stiefel(HS)conjugate gradient method and Polak-Ribiere-Polyak(PRP)conjugate gradient method.Under the condition of standard Wolfe line search,the proposed search direction is the descent direction.For general nonlinear functions,the method is globally convergent.Finally,numerical results show that the proposed method is efficient.
