This paper presents a novel coupled formulation for fluid-structure interaction (FSI) problems involving free-surface fluid flows, fracture phenomena, solid mutual contact and large displacements. The numerical formulation combines three different Lagrangian computational methods. The Particle Finite Element Method (PFEM) is used to solve the free-surface fluid flow, a Finite Element Method (FEM) with smoothed isotropic damage model is employed for the solution of solid structures and debris, finally, the Discrete Element Method (DEM) is used to manage the contact interaction between different solid boundaries, including the new ones generated by propagating cracks. The proposed method has a high potential for the prediction of the structural damages on civil constructions caused by natural hazards, such as floods, tsunami waves or landslides. Its application field can also be extended to fracture phenomena in structures and soils/rocks arising from explosions or hydraulic fracking processes. Several numerical examples are presented to show the validity and accuracy of the numerical technique proposed.

本文提出了一种新颖的耦合公式，用于流体-结构相互作用（FSI）问题，涉及自由表面流体流动，破裂现象，固体相互接触和大位移。数值公式结合了三种不同的拉格朗日计算方法。使用粒子有限元法（PFEM）求解自由表面流体流动，使用具有平滑各向同性损伤模型的有限元法（FEM）求解固体结构和碎屑，最后使用离散元法（DEM） ）用于管理不同实体边界之间的接触相互作用，包括由扩展裂纹产生的新边界。所提出的方法在预测洪水，海啸或山体滑坡等自然灾害对民用建筑造成的结构破坏方面具有很高的潜力。它的应用领域还可以扩展到由爆炸或水力压裂过程引起的结构和土壤/岩石破裂现象。给出了几个数值例子，以证明所提出的数值技术的有效性和准确性。