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Cables are slender structural elements, that are found in many engineering structures and are exposed to large displacements while experiencing small or large local strains during their installation or in dynamic environments. To address the complexity of their inner structure, an effective material model with anisotropic properties in the elastic and elastoplastic domain is utilized, allowing for...
The numerical simulation of particles that can be used as crash absorbers, for example, in ship collisions, is of high interest, as experimental investigation is often associated with high costs. After extensive studies on the breakage of single‐particles, the focus is now on the investigation of multi‐particle simulation. Although many parameter studies have been carried out for single‐particle compression...
The simulation of complex structures using standard finite element discretization techniques can be challenging because the creation of the boundary conforming meshes for such structures can be time‐consuming. Therefore, fictitious domain methods are attractive alternatives because the underlying mesh does not have to conform to the boundary. One fictitious domain method is the finite cell method...
The numerical investigation of cemented granular material (CGM) is a demanding task that requires the combination of various scientific disciplines. At the mesoscale, CGM is decomposed into the constituents of particles, cement matrix and void pores. The combination of these constituents, as found in nature or in civil infrastructure projects, creates a highly heterogeneous structure, whose morphology...
In previous years, research into the use of granular media as crash absorbers in a ship double hull has led to an increased interest in further optimisation to improve their energy absorption. One way is to add a coating layer on the outside surface of these particles. This work provides an introduction to the numerical modelling of coated particles to simulate their crushing behaviour. Depending...
Geometry conforming meshing techniques such as the finite element method (FEM) face a big challenge when dealing with complex and heterogeneous microstructures. Therefore, efficient simulation methods are needed combining accurate morphological reproducibility and computational efficiency. For such problems, the finite cell method (FCM) is a promising approach, which uses a Cartesian grid – independent...
The growing interest in granular materials used in mechanical applications, for example as crash absorbers in ship collisions, leads to an increased need for numerical models to simulate such granules. Since, in the case of an application as a crash absorber, the fracture behaviour of the granules is of particular interest, the numerical models must be able to simulate the breakage and predict, for...
The mechanical characterisation of cables can help improving the production and lifetime of various products, for example a robotic arm. Cables however form a class of composite structures, that is highly anisotropic and dissipates energy due to the reorientation of its constituents which is superimposed by the dissipation due to the deformation of the polymer components. Cables also have a degree...
Cables are slender structures with a complex geometry, that can undergo large deformations during their installation or in dynamic environments. In combination with their complex inner structure they pose a challenging problem for finite element simulations. In this article a simplified approach is presented to model cables by using an effective material and a homogeneous cross‐section, which is anisotropic...
In this work, a new adaptive integration method for simulation of two‐dimensional linear elasticity problems is presented. The main benefit of the proposed method is the reduction of the computational cost by lowering the number of integration points required to reach a certain level of accuracy. The main concept of the proposed method is to calculate new weights for trimmed cells employing the advantage...
The finite cell method (FCM) represents a combination of high‐order finite elements with the fictitious domain approach. Due to it's simple mesh generation the FCM reduces the pre‐processing effort. For heterogeneous problems of solid mechanics however, discontinuities occur at the material interfaces, which cannot be captured by the smooth shape functions of the FCM anymore, whereby the convergence...
In this contribution, a simple uniaxial compaction of granular materials is considered in preparation for studying the collision behavior of double‐hull vessels filled with granular materials. The top compressing plate is deformable and modeled by the finite element method (FEM). The particles modeled using the discrete element method (DEM) are compressed by the top plate. To this end, a partitioned...
The finite cell method (FCM) is based on an immersed boundary concept with high‐order finite elements. When solving nonlinear problems using the FCM, it is often difficult to reach to the desired load step because of the large distortion of the mesh, particularly when badly broken cells are existing in the mesh. To overcome this problem, a global remeshing strategy is proposed to allow the nonlinear...
In recent years, the idea of increasing the crash‐worthiness of ships by filling their double hull structure with granules has been studied. To this end, different granular materials have been investigated in [1, 2] with the result, that expanded glass materials are best suited for this purpose. Based on this work, it is important to gain deeper insights into the breakage behavior of expanded glass...
In the last years, classification societies have announced several specifications regarding the limitation of the noise level of ships. Accordingly, the prediction of the acoustic signature of cavitating propellers, which are the main source for noise generation, has attracted a lot of interest. For an accurate numerical simulation of the underlying physics, the deformation of the propeller has to...
Due to their complex structure cables exhibit an anisotropic behaviour and undergo large deformations in various applications. The large deformations are simulated using blended high order solid elements that can represent large deformations efficiently. To reduce the computational complexity the cross section consisting of many single wires and different layers of material is homogenized and represented...
In this paper, the use of hp‐basis functions with higher differentiability properties is discussed in the context of the finite cell method and numerical simulations on complex geometries. For this purpose, Ckhp‐basis functions based on classical B‐splines and a new approach for the construction of C1hp‐basis functions with minimal local support are introduced. Both approaches allow for hanging...
The paper presents some concepts of the finite cell method and discusses a posteriori error control for this approach. The focus is on the application of the dual weighted residual approach (DWR), which enables the control of the error with respect to a user‐defined quantity of interest. Since both the discretization error and the quadrature error are estimated, the application of the DWR approach...
Regarding new propeller materials and designs, vibrations and large deformations are becoming increasingly relevant. Therefore, simulation methods need to be developed which take into account the interaction of fluid and structure while retaining a computational effort suitable for the design stage. In the approach presented here, the fluid mechanical subproblem is solved by means of the software...
In this contribution, expanded glass granules are investigated, which will be used to increase the crashworthiness in ship construction. Therefore, an experimental setup is presented. This setup represents a simplified side hull structure of a double hull ship. The empty space between the double hull structure can be filled with the granular material which acts as crash absorber.
The described experiment...
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