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中文核心期刊

基于内聚力模型的高速水流聚脲基涂层剥离破坏模型研究

STUDY ON DEBONDING FAILURE MODEL OF POLYUREA-BASED COATING WITH HIGH VELOCITY WATER FLOW BASED ON COHESIVE ZONE MODEL

  • 摘要: 冲磨和空蚀破坏是水利水电设施最为常见的病害之一,严重影响水利水电设施的安全运行和效益发挥. 泄洪建筑物通常喷涂聚脲基涂层来提高抗冲耐磨性能,但在泄洪高速水流速度作用下抗冲磨聚脲基涂层的剥离破坏机理的研究尚属空白. 本文基于高速水流的流态形式,提出了高速水流对泄洪建筑物的力学作用模型,水流作用对泄洪建筑物的载荷主要包括拖曳力、冲击力、脉动力和上浮力;采用内聚力模型表征聚脲基涂层与泄洪建筑物防护体界面的剥离破坏过程,建立了高速水流聚脲涂层的剥离破坏模型, 给出了模型的有限元形式方程、本构关系以及损伤起始原则、演化原则和接触碰撞模型. 通过聚脲涂层与混凝土基底的剥离破坏试验,分析了不同剥离倾角下界面剥离破坏的拉应力与倾角之间的变化规律,得到了聚脲涂层剥离破坏过程中应力-\!-位移变化关系. 根据剥离破坏试验计算了界面剥离破坏断裂模型参数,采用数值方法对模型进行了验证,试验结果与模型计算结果吻合良好,为泄洪建筑物的抗冲耐磨设计提供理论依据.

     

    Abstract: The surface of the flood discharge building is usually sprayed with polyurea-based coating to improve the impact resistance. However, the research on the debonding failure mechanism of the anti-wear polyurea-based coating under the action of high-speed water flow velocity is still blank. Based on the flow pattern of high-velocity water flow, the mechanical model of high-velocity water flow to flood-discharge building was determined, and the load on flood discharge building caused by high-velocity water flow mainly includes drag force, impact force, fluctuating force and lifting force. The cohesive zone model was used to characterize the debonding failure process of the interface between polyurea-based coating and flood-reducing building, and the debonding failure model of polyurea-coating with high-speed water flow was established, and the finite element formal equations, constitutive relationship, damage initiation principle, evolution principle and contact and collision model of the model are given. The relationship between stress-displacement in the process of debonding failure was obtained by the debonding failure tests, and the variation law between peeling failure stress and inclination angle of interface was obtained. According to the peeling failure test, the parameters of debonding failure model were obtained, and the model was also verified. The test results were in good agreement with the model calculation results, which provides a theoretical basis for the anti-shock and wear-resistant design of flood discharge building.

     

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