Abstract ：

为实现海上风电机组支撑结构抗疲劳设计,提出基于整体-局部方式建模的疲劳分析方法.利用该方法对热点局部区域进行详细有限元建模,基于IIW规范采用高精度六面体实体单元离散,其余非重点区域采用梁单元离散,可克服以往运用应力影响矩阵研究中忽略整体结构位移、边界条件不易施加等缺点.基于IEC 61400规范进行整机动力学和载荷计算,对某海上风电机组三脚架支撑结构进行疲劳分析.对比分析不同载荷工况、波高和水深下的累积损伤值,结果验证了所提出的整体-局部建模方法在海上风电机组三脚架支撑结构疲劳分析中的可行性和优越性.

Keyword ：

疲劳载荷 疲劳损伤 海上风电机组 抗疲劳性 网格划分

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Abstract ：

To realize the anti-fatigue design of offshore wind turbine support structures，a whole-local modeling-based fatigue analysis method was proposed. A detailed finite element model was established for the local hot spot regions. On the basis of the IIW specification，high-precision hexahedral solid elements were utilized for discretization，whereas beam elements were used to discretize non-critical areas. The proposed method overcomes the deficiencies of previous studies employing stress influence matrix，such as ignoring the displacement of the entire structure and making it difficult to apply the boundary conditions. Using IEC 61400 standards，the dynamic behavior and loads of the entire turbine were calculated and a fatigue analysis of the tripod support structure of an offshore wind turbine was performed. The cumulative damage values caused by various load conditions，wave height and water depth are compared and analyzed. The results demonstrate the viability and superiority of the proposed whole-local modeling method for fatigue analysis of offshore wind turbine tripod support structures. © 2024 Science Press. All rights reserved.

Keyword ：

mesh generation offshore wind turbines fatigue load fatigue damage fatigue resistance

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Abstract ：

Recognizing importance and difficulty of the fatigue design of high and flexible wind turbine steel tubular tower structures, this study discusses the corresponding wind-induced fatigue analysis theory and approach as well as their application to a typical wind turbine structure. An integrated finite element model is established including blades, nacelle, tubular tower and foundation. The joint distribution function of wind speed and wind direction at the installation location of the wind turbine structure is then derived based on the observation data of the meteorological station. The wind-induced response time-domain analyses of the wind turbine structure are carried out. Time-domain and time-frequency domain analysis theories are systematically established considering the effect of blade rotating, wind direction and the impact of low stress amplitude cycle on the fatigue damage of tubular tower steel structures. The results show that the rotating effect of blades has significant influent on the root mean square (RMS) of steel tubular tower structures, therefore the wind-induced fatigue life analysis should consider the rotating effect of blades. Wind direction has great influence on wind-induced fatigue cumulative damage, which is larger in the interval with a higher probability of wind direction. The fatigue life of the steel tubular tower structures calculated through time-frequency domain analysis theory is relatively small, and the calculation cost is smaller compared with that based on time domain analysis theory. The equivalent stress method modified by the rain flow method, TB-2 formula and Dirlik formula are proposed to make fatigue design for wind turbine tubular tower structures in this study. Corresponding to different design requirements in practical engineering, different wind-induced fatigue analysis methods are recommended. © 2023 Tsinghua University. All rights reserved.

Keyword ：

influence of low stress range on fatigue damage wind turbine steel tubular towers rotating effect of blades wind direction time-frequency domain wind-induced fatigue analysis methods

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Abstract ：

高耸、轻柔的风力机钢塔筒结构在风荷载作用下的抗疲劳设计是一项重要且难度较大的工作,该文主要探讨其风致疲劳的分析理论与方法,并在某典型风力机结构中加以应用.建立了包含"叶片-机舱-塔筒-基础"的风力机结构整体有限元模型;基于气象站的气象资料推导得到了风力机位置处的风速风向联合分布函数;对风力机钢塔筒结构进行了风振响应时域分析,系统地建立了风力机钢塔筒结构合理考虑叶片旋转效应、风向及低应力幅循环对疲劳损伤有折减影响的风致疲劳寿命时域和时-频域分析方法.研究表明:叶片旋转效应对钢塔筒响应的均方根值影响较为显著,风力机钢塔筒结构风致疲劳寿命分析需考虑叶片的旋转效应.风向对钢塔筒结构的风致疲劳累积损伤影响较大,在风向出现概率较大的区间产生的风致疲劳累积损伤较大.相对于时域分析方法,时-频域分析方法计算得到的钢塔筒结构疲劳寿命均偏低,且计算较简便.建议采用雨流修正后的等效应力法、TB-2和Dirlik公式来进行风力机钢塔筒结构的风致疲劳寿命预测分析.针对实际设计需求,兼顾安全性和经济性,建议采用不同的风致疲劳分析方法.

Keyword ：

时-频域风致疲劳分析方法 叶片旋转效应 风向 风力机钢塔筒 低应力幅疲劳损伤影响

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本发明公开了一种PA/GF齿轮的疲劳寿命预测方法，包括步骤：通过SOLIDWORKS建立齿轮副模型；在Adams中模拟实际工况，获取载荷谱；在ANSYSWorkbench的静力学模块进行材料设定，网格划分，载荷施加，边界条件设定。将静力学模块与ANSYSnCodeDesignLife中的应力疲劳分析模块建立连接后，在ANSYSnCodeDesignLife中进行导入有限元模型，导入载荷谱，进行SN曲线拟合，选定疲劳准则进行寿命仿真。本发明的优点是：提出了一种纤维复合材料齿轮的疲劳寿命预测方法，并进行疲劳寿命预测，提高了PA/GF齿轮疲劳寿命的有限元仿真预测的准确性，节约了试验成本，提高了效率。

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Abstract ：

本发明涉及一种基于结合K‑S函数的连续体结构疲劳拓扑优化设计方法，包括以下步骤：(1)输入结构的几何尺寸，赋予弹性模量、泊松比、密度等材料属性，建立基结构有限元模型；(2)输入疲劳拓扑优化参数，形成优化模型；(3)初始化变量并获取基结构信息；(4)对结构进行疲劳分析，提取分析结果；(5)引入质量和疲劳过滤函数、K‑S函数、拉格朗日乘子构建拉格朗日方程，实现对优化模型的显式化；(6)利用Kuhn‑Tucker方法对优化模型进行求解，获得满足质量收敛精度的连续拓扑变量解；(7)对连续拓扑变量解进行反演，获得离散拓扑变量，使结构满足疲劳寿命约束，获得最优拓扑结构。本发明从概念设计阶段便将疲劳寿命的影响考虑在内，对于考虑疲劳特性的工程结构设计具有重要意义。

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Abstract ：

一种基于全局化求解策略的疲劳结构拓扑优化设计方法涉及结构中材料的布局设计，适用于考虑疲劳特性的结构初始概念设计。本发明包括以下步骤：(1)建立基结构有限元模型；(2)输入疲劳拓扑优化参数，形成优化模型；(3)初始化变量并获取基结构信息；(4)对结构进行疲劳分析，并提取分析结果；(5)引入过滤函数，实现对优化模型的显式化；(6)对优化模型进行求解，获得最优连续解；(7)对最优连续解进行离散反演，使结构满足优化准则判断，从而获得最优拓扑结构。本发明提出了解决结构疲劳特性的结构优化设计，不再是对结构优化的参数优选，从概念设计阶段便将疲劳寿命的影响考虑在内，对于考虑疲劳特性的工程结构设计具有重要意义。

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Abstract ：

为了研究钢丝绳直径、结构和环境温度对钢丝绳疲劳寿命的影响,选择用于太空安全绳的钢丝绳,通过Ansys Workbench分析软件建立钢丝绳多场耦合有限元模型,计算不同因素对钢丝绳应力的影响。根据应力疲劳理论,导入不锈钢材料的应力-寿命曲线,对钢丝绳的疲劳寿命进行仿真分析,通过钢丝绳的疲劳寿命云图可以发现,钢丝绳的直径和结构对钢丝绳的疲劳寿命影响较大,环境温度对钢丝绳的疲劳寿命影响较小。根据仿真结果和具体使用条件,遴选出最适合用于太空安全绳的钢丝绳。

Keyword ：

Ansys Workbench 应力疲劳理论 钢丝绳 多场耦合

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Abstract ：

为了探讨2219-T6铝合金搅拌摩擦焊接头疲劳断裂位置与区域局部力学性能及材料微观结构之间的关系,对铝合金2219-T6搅拌摩擦焊接头开展了疲劳试验研究.试样接头疲劳断裂处大多位于焊核区与热机区交界处及临近区域,在裂纹萌生处的亚表面发现有大的夹杂.焊核区有明显微空洞,小角度晶界最多.利用ABAQUS软件数值模拟接头疲劳,分析了接头局部区域力学性能.接头的热机区和焊核区的主应变值较大,这些区域较其他区域更易萌生疲劳裂纹.

Keyword ：

接头 数值模拟 疲劳断裂 搅拌摩擦焊

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Abstract ：

　　波纹管的疲劳分析有助于提高波纹管的力学性能。本文利用ProE建立波纹管模型，通过Ansys Workbench数值仿真计算，得到了不同壁厚的波纹管在相同工作条件下的疲劳寿命云图，研究了厚度对波纹管疲劳寿命的影响规律。研究结果对于波纹管的优化设计具有一定的理论依据。

Keyword ：

波纹管 疲劳 Ansys Workbench软件

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