buckling

说明：  通过频谱来模拟波浪，程序为Jonswap谱的波浪模拟，可随意调整谱参数、时间间隔和模拟的时间长度(The wave is simulated by the spectrum, and the program is a wave simulation of the Jonswap spectrum. The spectral parameters, time interval and length of the simulation can be adjusted at will.)

本文首先分析了永磁同步电机矢量控制的发展概况，然后从机电能量转换的角度出发，解释三相永磁同步电机的机电能量转换原理，推导拉格朗日运动方程。此外，列写出永磁同步电机在三相静止坐标系和dq坐标系下的数学模型。基于Simulink建立了转速电流双闭环矢量控制系统的仿真模型，通过对仿真结果分析，验证了永磁同步电机矢量控制系统性能的优越性。(This paper first analyzes the development of permanent magnet synchronous motor vector control, and then explains the electromechanical energy conversion principle of three-phase permanent magnet synchronous motor from the perspective of electromechanical energy conversion, and deduce the Lagrange motion equation. In addition, the mathematical model of permanent magnet synchronous motor (PMSM) in three phase stationary coordinate system and dq coordinate system is listed. Based on Simulink, a simulation model of speed and current double closed loop vector control system is established. By analyzing the simulation results, the performance of PMSM vector control system is verified.)

说明：  蚁群算法用来函数寻优，本代码给出了通用版本，能够很好的适应和学习(Ant colony algorithm is used to function optimization, this code gives a general version, can adapt and learn well)

纳入了机械损伤和应变速率的断裂UMAT子程序，不能用于平面应力。(The fracture UMAT subroutine incorporating mechanical damage and strain rate can not be used for plane stress.)

分别对matlab和ansys两种平台的拓扑优化结果分析比较，为学习者提供了两种不同优化设计思路，过程详细清晰，易于学习理解(The analysis and comparison of topology optimization results between MATLAB and ANSYS two platforms provide two different optimization design ideas for learners. The process is clear and clear, and easy to learn and understand.)

说明：  主要可以用来研究疲劳累积循环载荷作用下损伤与断裂问题，(It can be used to study the damage and fracture under the fatigue cumulative cyclic load,)

实现调频仿真，用于系统组合使用，检测；可进一步用于各种调频的使用。(Realization of FM simulation)

一个用于模拟声波在非线性介质中传播的matlab工具箱，可以用来进行超声相关的实验。(Realization of ultrasonic simulation)

用abaqus做的金属切削仿真，希望可以帮助大家(A metal cutting simulation, i hope it will be helpful)

说明：  本模型采用abaqus自带的connector连接单元建模，实现了钉节点的模拟(In this model, the connector unit of ABAQUS is used to simulate the nail node)