Hygrothermal fracture analysis of fibrous composites with variable fiber spacing using JK-integral

Download
2013
Saeidi, Farid
In this study, a Jk-integral based computational method will be developed to conduct fracture analysis of fibrous composite laminates that possess variable fiber spacing. This study will be carried out for the fibrous composites exposed to not only thermal but also hygroscopic boundary condition, which results hygrothermal load. Formulation of the Jk-integral will be carried out by using the constitutive relations of plane orthotropic hygrothermoelasticity. One of the most important challenges of this study is to change Jk-integral formulation into domain independent form, because dealing with infinitely small domains in solving the integral would be frustrating. Developed form of Jk-integral will be merged to ANSYS, a finite element analysis software. Numerical results will be generated so as to assess the influence of variable fiber spacing on the modes I and II stress intensity factors, energy release rate, and the T-stress. For validation and comparison, some of the results are also obtained using Displacement Correlation Technique (DCT).

Suggestions

Mixed mode fatigue crack growth path and life prediction under variable amplitude loading through extended finite element method
Dirik, Haydar; Yalçınkaya, Tuncay; Department of Aerospace Engineering (2017)
The main purpose of this study is to predict the crack growth path trajectories and fatigue crack growth (FCG) life under variable amplitude loading (VAL) by using Extended Finite Element Method (XFEM). For this purpose a computational algo- rithm is developed in Fortran which interacts with a commercial finite element soft- ware (Abaqus) and automatically propagates cracks which is initially modelled as stationary crack. Nasgro FCG equation is used for FCG life calculation which has a great accuracy among t...
Thermal fracture analysis of orthotropic functionally graded materials using an equivalent domain integral approach
Dağ, Serkan (2006-12-01)
A new computational method based on the equivalent domain integral (EDI) is developed for mode I fracture analysis of orthotropic functionally graded materials (FGMs) subjected to thermal stresses. By using the constitutive relations of plane orthotropic thermoelasticity, generalized definition of the J-integral is converted to an equivalent domain integral to calculate the thermal stress intensity factor. In the formulation of the EDI approach, all the required thermomechanical properties are assumed to ha...
Failure analysis of tapered composite structures under tensile loading
Çelik, Ozan; Parnas, Kemal Levend; Department of Mechanical Engineering (2016)
A three dimensional finite element modeling approach is used to evaluate the effects of preliminary design variables on the performance of tapered composite laminates under tensile loading. Hashin failure criteria combined with a progressive failure algorithm is used for in-plane failure mechanisms and cohesive zone method is used for out-of-plane failures. The modeling approach is validated by a comparison with experimental results from literature. The validated model is used to examine various design vari...
Computational elastodynamics of functionally graded thick-walled cylinders and annular coatings subjected to pressure shocks
Abeidi, Abdelrahim; Dağ, Serkan (2022-12-01)
A computational technique based on domain-boundary element method (D-BEM) is developed for elastodynamic analysis of functionally graded thick-walled cylinders and annular coatings subjected to pressure shock type of loadings. The formulation is built on the wave equation, which is derived in accordance with plane elastody-namics. Weighted residual statement for the wave equation is expressed by using the static fundamental solution as the weight function. Applying integration by parts and incorporating the...
Elastic Response of Heat Generating Rod at a Variable Generating Rate
Eraslan, Ahmet Nedim; Varlı, Ekin (2014-09-28)
The aim of this study is to develop a computational model to analyze thermally induced stress and deformation in a heat generating solid rod. The rod is initially at zero temperature, but for times greater than zero heat is generated internally at both space and time dependent rate. As the rod is heated up slowly an uncoupled solution is realized. The heat conduction equation with a variable generation rate is solved by a finite element collocation method. Two different generation rates are handled. The num...
Citation Formats
F. Saeidi, “Hygrothermal fracture analysis of fibrous composites with variable fiber spacing using JK-integral,” M.S. - Master of Science, Middle East Technical University, 2013.