When simulating pressure-driven fracture with the Finite Element Method (FEM), significant difficulties can arise upon representing newly formed complex damage surfaces and their concurrent crack face loading. Application of this loading can also be required when additional physics is involved as in the case of hydraulic fracture where fluid physics inside a damage need to be considered. This paper presents a new Finite Element based practical numerical framework which can model pressure-driven fractures as they form on-the-fly without remeshing. The exact location of physical discontinuities passing through the element domain can be represented in the numerical model. The numerical framework can be implemented as a user-defined element and can be integrated into any FE package. A new element (called pressure element) is formulated with the capability to apply pressure and associated forces onto the crack surfaces in an adaptive manner. This element is verified using relevant examples from literature. The framework can also be configured for multi-physics problems where crack face loading is dictated by an additional physics. The element formulation is then extended for multi-physics problems involving fluid–solid interaction. The formulation provides the capability for multi-physics coupling adaptively as the crack propagates. The element is used to successfully simulate a test case from literature using different solution procedures (iterative and simultaneous). This element is also used to model failure in different pressure vessel problems to demonstrate its potential use in structural applications. A new higher-scale vessel element is developed which can represent different size, partitioning and failure states of composite vessel systems at element level. Composite vessel failure involving high number of pressurized cracks and delaminations as well as their interaction is modelled, and burst pressures are predicted for different vessel systems. The proposed numerical framework can be used towards designing more damage-tolerant vessels critical for the sustainable propulsion technologies.

中文翻译：

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一种新的基于浮动节点的单元公式，用于对压力驱动断裂进行建模


当使用有限元法 （FEM） 模拟压力驱动断裂时，在表示新形成的复杂损伤表面及其并发的裂纹面载荷时可能会出现重大困难。当涉及额外的物理场时，也可能需要施加这种载荷，例如在水力裂缝的情况下，需要考虑损伤内部的流体物理。本文提出了一种新的基于有限元的实用数值框架，该框架可以在动态形成压力驱动裂缝时对其进行建模，而无需重新划分网格。通过单元域的物理不连续性的确切位置可以在数值模型中表示。数值框架可以作为用户定义的元素实现，并且可以集成到任何 FE 包中。制定一个新的单元（称为压力单元），能够以自适应方式将压力和相关力施加到裂纹表面上。该元素使用文献中的相关示例进行了验证。该框架还可以针对多物理场问题进行配置，其中裂纹面载荷由额外的物理场决定。然后，将单元公式扩展到涉及流-固相互作用的多物理场问题。该公式提供了在裂纹传播时自适应地进行多物理场耦合的能力。该元素用于使用不同的求解过程（迭代和同时）从文献中成功模拟测试用例。该单元还用于模拟不同压力容器问题中的失效，以展示其在结构应用中的潜在用途。开发了一种新的更高尺度的容器单元，它可以在单元级别表示复合材料容器系统的不同尺寸、分区和失效状态。 对涉及大量加压裂纹和分层及其相互作用的复合材料容器失效进行建模，并预测不同容器系统的爆破压力。所提出的数值框架可用于设计对可持续推进技术至关重要的更耐损的船舶。