In this paper, a mathematical model for topology optimization oftruss structures with constraints of displacement and systemreliability under multiple loading cases is constructed. In order toavoid the difficulty of c...In this paper, a mathematical model for topology optimization oftruss structures with constraints of displacement and systemreliability under multiple loading cases is constructed. In order toavoid the difficulty of computing the structure's system reliability,a solving approach is presented in which the failure probability ofsystem is divided into the sum of a all bars' failures probability bymeans of reliability distribution. In addition, by drawing into thereliability safety factor and the fundamen- tal relationship instructural mechanics, all probability constraints of displacement andstress are equiv- alently displayed as conventional form and linearfunction of the design variables.展开更多
在风力发电机组吊装完成和高风速切出或故障切出时,机组保持在空转停机状态。在现场特定风况和特定机组状态组合下,叶片容易发生由动态失速导致的振荡现象,极大威胁叶片疲劳寿命和机组安全性。根据IEC 61400-1规范中的要求,机组处于空...在风力发电机组吊装完成和高风速切出或故障切出时,机组保持在空转停机状态。在现场特定风况和特定机组状态组合下,叶片容易发生由动态失速导致的振荡现象,极大威胁叶片疲劳寿命和机组安全性。根据IEC 61400-1规范中的要求,机组处于空转停机状态,应考虑极端风速模型(EWM)。针对叶片长度分别为92、97、112 m 3款叶片进行建模分析,研究机组发生失速振荡的内在规律和抑制手段。通过对机组在0~360°风向、场址极端风速以及降低风况条件进行Bladed仿真,发现3款机组均在1只叶片竖直向下位置附近、风向30°和330°附近容易发生叶片失速振荡现象。基于失速振荡发生较为集中的工况,通过调整桨距角能够实现对振荡幅值的抑制;针对不同气动外形,抑制效果有一定差别。展开更多
基金the National Natural Science Foundation of China
文摘In this paper, a mathematical model for topology optimization oftruss structures with constraints of displacement and systemreliability under multiple loading cases is constructed. In order toavoid the difficulty of computing the structure's system reliability,a solving approach is presented in which the failure probability ofsystem is divided into the sum of a all bars' failures probability bymeans of reliability distribution. In addition, by drawing into thereliability safety factor and the fundamen- tal relationship instructural mechanics, all probability constraints of displacement andstress are equiv- alently displayed as conventional form and linearfunction of the design variables.
文摘在风力发电机组吊装完成和高风速切出或故障切出时,机组保持在空转停机状态。在现场特定风况和特定机组状态组合下,叶片容易发生由动态失速导致的振荡现象,极大威胁叶片疲劳寿命和机组安全性。根据IEC 61400-1规范中的要求,机组处于空转停机状态,应考虑极端风速模型(EWM)。针对叶片长度分别为92、97、112 m 3款叶片进行建模分析,研究机组发生失速振荡的内在规律和抑制手段。通过对机组在0~360°风向、场址极端风速以及降低风况条件进行Bladed仿真,发现3款机组均在1只叶片竖直向下位置附近、风向30°和330°附近容易发生叶片失速振荡现象。基于失速振荡发生较为集中的工况,通过调整桨距角能够实现对振荡幅值的抑制;针对不同气动外形,抑制效果有一定差别。