大型开式齿轮损伤强度数值模拟分析

摘要

以某自升式平台齿轮、齿条升降系统为原型,基于数值模拟方法研究损伤对于大型开式齿轮强度的影响.利用有限元软件ANSYS建立自升式平台齿轮、齿条三维模型,定义齿轮表面硬化层与基体材料属性,用弹塑性方法分析平台在预压工况下齿轮、齿条的应力分布并将其与弹性分析结果进行对比.建立磨损、点蚀、裂纹齿轮模型并进行啮合模拟分析,研究不同损伤形式对于齿轮强度的影响.结果表明:齿面损伤的存在改变了啮合过程中轮齿上应力应变的分布,磨损使得塑性变形增大；点蚀和裂纹造成局部应力集中,将不同程度地降低齿轮的承载能力.%Taking the rack and pinion jacking system of some jack-up platform as prototype, the influence of the damages on the strength of large-scale open gears was studied based on the numerical simulation. The three-dimensional models of the rack and pinion of the jack-up platform were firstly built up using ANSYS. The material properties of the hardened layer and the base metal were defined respectively. The stress distribution of rack and pinion was analyzed using elastic-plastic analysis method under preload condition and the results were compared with those of elastic analysis. The three-dimensional models of pinions with abrasion, pitting and crack were built up and meshing analysis was performed for them respectively. The influence of the damages on the gear strength was studied. The results show that the distribution of stresses and strains on the tooth is affected by these damages. The abrasion brings to bigger plastic deformation. The pitting and crack leads to local stress concentration. All these will decrease the bearing capacity of the gears.