Constitutive modeling and characterization of C/C-SiC CMC material

Ceramic matrix composites (CMCs) are advanced materials that consist of a ceramic matrix reinforced with a high-strength, high-stiffness material, such as carbon fibers. They offer excellent thermal and chemical stability while exhibiting low weight and exceptional mechanical properties. A novel CMC material is the C/C-SiC produced with 2/2...

Fatigue analysis of wind turbine blade materials using a continuum damage mechanics framework

The work done for this thesis is related to fatigue analysis of various material types used in the wind turbine blades. For the analysis, a framework from the thermodynamics of irreversible processes with internal variables and Continuum Damage Mechanics (CDM) is used. Thermodynamic principles provide a generic framework that is valid for the...

Analysis Methodologies for As-Manufactured Composite Pressure Vessels

Type IV composite pressure vessels (CPVs) are used commercially for the gaseous storage of hydrogen in fuel cell electric vehicles (FCEVs). However, their economic implementation requires material optimization and a reliable prediction of the vessel strength. In this regard, their burst when loaded under internal pressure is impacted by the...

The Myth of Softening behavior of the Cohesive Zone Model Exact derivation of yield drop behavior of wood

It is shown that the postulate of strain softening of the fracture stress is based on the error to regard the nominal stress to be the actual, ultimate stress, at the actual area of the fracture plan. Strain sof-tening called yield drop is elastic unloading of the actual elastic stress at the intact, not ltimate, elas-tic loaded part of the...

Material model for wood

Wood is highly anisotropic and shows ductile behaviour in compression and brittle behaviour in tension and shear where both failure modes can occur simultaneously. A 3D material model for wood based on the concepts of continuum damage mechanics was developed. A material subroutine containing the developed model was implemented into a standard FE...

Constitutive model for wood based on continuum damage mechanics

Mechanical behaviour of timber joints with slotted-in steel plates

Timber joints are a key part of timber structures. Their reliable performance is a prerequisite to successful timber construction. The structural loadbearing behaviour of timber joints is mechanically complex and difficult to predict. Although numerical tools are currently available, these do not consider all anisotropic aspects of timber....

Constitutive modelling of hyperelastic rubber-like materials

The simulation of rubber-like material behaviour by means of the finite element method has been described in this study. Proper material models were selected for the numerical description of static hyper-elasticity. The combinations of a continuum damage mechanics concept and a pseudo-elastic concept with Gao's elastic law were used to simulate...

Computational modelling of rubber-like materials under monotonic and cyclic loading

The simulation of rubber-like material behaviour by means of the finite element method has been described in this study. Proper material models for the numerical description of static hyper-elasticity, the ideal Mullins effect and the Mullins effect with permanent deformation were proposed, respectively. The second focus of this study was the...