Circular Image

62 records found

Authored

This paper presents a new polymorphic element modelling approach for multi-scale simulation, with an application to fracture in composite structures. We propose the concept of polymorphic elements; these are elements that exist as an evolving superposition of various states, e ...

The cohesive element (CE) has been widely used to model delamination in laminated composites. The penalty stiffness, interfacial strength and fracture toughness are three CE parameters that often determine the accuracy of the numerical analysis by finite elements (FEs). The fract ...

In this paper, the recently-developed floating node method is extended for damage analysis of laminated composites with large deformations. Strong discontinuities including interfacial delamination and matrix cracks are explicitly represented by geometrically nonlinear kinemat ...

The Floating Node Method (FNM), first developed for modeling the fracture behavior of laminate composites, is here combined with a domain-based interaction integral approach for the generic fracture modeling of quasi-brittle materials from crack nucleation, propagation to fina ...

A three-dimensional separable cohesive element (SCE) is proposed to enable the modelling of interaction between matrix cracking and interfacial delamination in laminated fibre-reinforced composite materials. It is demonstrated that traditional cohesive elements are incapable o ...

The cohesive element has been widely employed to model delamination and matrix cracking in composite materials. However, an extremely fine mesh along the potential crack path is required to achieve accurate predictions of stresses within the cohesive zone. A sufficient number ...

Contributed

Identification of mine blast interaction pressure on excited plates

Using transient adjoint optimization for solving the inverse problems

Mines and improvised explosive devices are the cause of many mortalities of vehicle occupants. Both experimental and numerical research in this field aims to improve the safety of military vehicles. TNO has advanced Finite Element (FE) models to simulate such events. The numerica ...
Compressive failure mechanisms of fiber reinforced polymers represent a significant challenge when accurately modeling common industrial problems. This thesis aims to deliver a physically representative computational framework capable of simulating Open Hole Compression. A novel ...
This thesis is part of a greater effort to use machine learning for the development of flexible and universal unresolved-scale models in large eddy simulation (LES). The novelty in the current work is that a neural network learns to predict the integral forms of the unresolved-sc ...

C1 Cohesive Element Models for 3D Delamination

Towards overcoming the mesh density constraint in FE delamination analyses

The wide adoption of composite structures in the aerospace industry asks for reliable numerical methods to account for the effects of damage, among which delamination. Cohesive elements (CEs) are a versatile and physically representative way of reproducing delamination, but, usin ...
This thesis presents a model that is able to predict fatigue crack growth and damage directionality in non-conventional Fibre Metal Laminates (FMLs) in CentreCracked Tension (CCT) specimens. Non-conventional FMLs encompass all FMLs other than standardised ones such as GLARE. FMLs ...
Engineering fields such as aerospace rely heavily on the Finite Element Method (FEM) as a modelling tool. In combination with the scale and complexity of the structures typically involved here, computational cost remains a traditional issue. To perform FEM analyses of such struct ...
New methods for aircraft movables introduce oblique- and out-of-plane loads on lug joints. With the introduction of these loads on lugs the need arises for a more detailed fatigue life prediction method.

Therefore, the thesis research focused on creating a methodology f ...

High Order Adaptively Integrated Cohesive Elements

Development, implementation and testing on composite delamination

Composite delamination represents one of the most critical failure mechanisms occurring in composite structures. In case complex structures are being designed, numerical methods need to be employed. One of the methods to numerically simulate delamination in a Finite Element envir ...

Structural health monitoring of impact damage for composite aircraft structures

Investigating the damage severity estimation of an image reconstruction technique using PZT sensors

The high specific strength and stiffness of composite materials have resulted in a widespread introduction of composite structures in the commercial aviation industry. Although composite materials offer the possibility to design lightweight structures, they also suffer from compl ...
Fibre-reinforced composites have become increasingly attractive for many engineering applicationsin the last decades. A very interesting aspect of these materials is that their mechanical properties canbe tailored for optimum strength and stiffness by controlling the orientation ...
Crack initiation and propagation in composite structures exists as a prominent knowledge gap in computational fracture mechanics. Prior to the development and implementation of fracture modules in FEM solvers, most studies were constrained to simple geometries and load cases. The ...
The dutch government plans to build a vast amount of offshore wind turbines. Therefore, it will be necessary to decrease the costs of the transportation, installation and maintenance of these wind turbines. Jules Dock tries to achieve this by replacing the steel design of the nex ...
Near free edges of fibre reinforced composite laminates modelled with homogeneous layers, the presence of high gradient interlaminar stresses has been found theoretically. Over a span of nearly 50 years, various methods, including numerical and analytical have been employed for a ...