Abstract:

Aiming at the repeated braking conditions of offshore drilling drawworks during the round trip,a three-dimensional FEM of thermo-mechanical coupling analysis of the water-cooling brake disc was established.By using  the FEA software ABAQUS,the repeated braking process was simulated.Distribution characteristics of the surface and inner temperature field and stress field were obtained,based on which,the thermal fatigue failure mechanism of brake disc was analyzed.The results show that,in the repeated braking,
the temperature and stress of brake disc are coupled,and they have the similar variation disciplinarian.Thermal stress in the circular direction is the main stress for causing the initial cracks on the surface of brake disc.These cracks are getting larger under the effect of repeated thermal stress,eventually,inducing the fracture of brake disc.The analysis results are in good agreement with the practical situation,
which prove the validity and feasibility of the analysis method used herein.

Key words: water-cooling disc brake, repeated braking, temperature field, stress field, thermal fatigue cracks

摘要：

针对海洋钻井绞车在连续下钻过程中的制动工况,建立了水冷盘式制动器三维热—机耦合分析模型,运用大型有限元分析软件ABAQUS数值模拟了制动器的制动过程,获得了制动盘表面及内部温度场与应力场的分布特征,并以此为基础分析了制动盘热疲劳失效的机理。研究结果表明：连续制动工况下,制动盘的温度场与应力场相互耦合,两者具有相似的变化规律;周向热应力是形成制动盘表面初始裂纹的主要应力分量,在热应力反复作用下,该初始裂纹发展为粗大的裂纹,最终导致制动盘的断裂。分析结果与实际情况吻合较好,从而证明了该分析方法的正确性和可行性。
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关键词: 水冷盘式制动器, 连续制动, 温度场, 应力场, 热疲劳裂纹