scholarly journals An extended cohesive damage model study of geometrical ratio effects on failure mechanisms of functionally graded sandwiches with multi-layered cores

2019 ◽  
Vol 224 ◽  
pp. 110999
Author(s):  
S. Ghimire ◽  
J. Chen
Keyword(s):  
Failure Mechanisms ◽  
Damage Model ◽  
Functionally Graded ◽  
Model Study ◽  
Cohesive Damage

Failure Mechanisms and Damage Model of Ductile Cast Iron Under Low-Cycle Fatigue Conditions

2014 ◽  
Vol 45 (11) ◽  
pp. 5085-5097 ◽  
Author(s):  
Xijia Wu ◽  
Guangchun Quan ◽  
Ryan MacNeil ◽  
Zhong Zhang ◽  
Clayton Sloss
Keyword(s):  
Cast Iron ◽  
Low Cycle Fatigue ◽  
Failure Mechanisms ◽  
Damage Model ◽  
Ductile Cast Iron ◽  
Cycle Fatigue

scholarly journals An Advanced Finite Element Modeling for the Failure of Notched Ceramic Matrix Composite With TFP Patch Reinforcement

2021 ◽  
Vol 8 ◽  
Author(s):  
Gang Zhao ◽  
Jianbo Tang ◽  
Jun Wang ◽  
Yunsheng Chen ◽  
Yajie Feng ◽  
...  
Keyword(s):  
Matrix Composite ◽  
Failure Mechanisms ◽  
Damage Model ◽  
Ceramic Matrix Composite ◽  
Mesh Size ◽  
Ceramic Matrix ◽  
Damage And Failure ◽  
Virtual Test ◽  
Modeling Strategy ◽  
Progressive Damage Model

An advanced modeling strategy for notched ceramic matrix composite coupons with patch reinforcement was proposed to investigate the failure mechanisms. This model considered the tailored fiber–placed (TFP) yarn details obtained from the design phase and the embedded element concept which was used to successfully overcome the meshing difficulties. Inter-ply “glue” layers were simulated using the surface-based contact cohesive element method, so the delamination due to interfacial material discontinuity and damage can be well reproduced and analyzed. For composite ply, the energy-based composite progressive damage model that is independent of the mesh size was applied. Virtual test campaign was performed with a variety of geometrical and material parameters, and the damage and failure mechanisms based on the stress analysis can be revealed to support the design optimization of patch reinforcement.

Numerical studies on mixed-mode crack propagation behavior for functionally graded material based on peridynamic theory

2018 ◽  
Vol 07 (04) ◽  
pp. 1850027 ◽  
Author(s):  
Fei Wang ◽  
Yu’e Ma ◽  
Yanning Guo ◽  
Wei Huang
Keyword(s):  
Crack Propagation ◽  
Mixed Mode ◽  
Fracture Behavior ◽  
Damage Model ◽  
Fortran Program ◽  
Functionally Graded ◽  
Mixed Mode Fracture ◽  
Stress Load ◽  
Gradient Direction ◽  
Mixed Mode Crack

Peridynamics (PD) is a new nonlocal theory that unifies the mechanics of discrete particles, continuum, and continuum with discontinuities, and it has inherent advantages in calculating the mixed-mode crack propagating. Functionally graded materials (FGMs) are the advanced composite materials, fracture behavior of which is complicated to be simulated by the traditional continuum mechanics. Hence, a PD model for FGMs is given to investigate the mixed-mode fracture behavior under quasi-static loading. Basic PD equations, damage model, and PD [Formula: see text]-integral for FGMs are discussed. A FORTRAN program of PD algorithm is coded to calculate the [Formula: see text]-integral and crack propagation of FGMs. The [Formula: see text]-integral and the crack paths of the PD model are verified by comparing with the published numerical and experimental results. Effects of the material gradient, the material gradient direction, and the stress load magnitude on the fracture behavior are investigated. It is shown that the PD [Formula: see text]-integral and the crack path are strongly affected by the material gradient and the gradient direction under the same stress load. When the gradient of FGMs is linear, the material gradient direction decides whether the mixed-mode crack kinks or not and the magnitude of stress determines the kinking angle.

Strengthening and Retrofitting Strategy for Masonry (New Build Construction in Indonesia)

2016 ◽  
Vol 845 ◽  
pp. 181-187 ◽  
Author(s):  
Gede Adi Susila ◽  
Parthasarati Mandal ◽  
Thomas Swailes
Keyword(s):  
Material Properties ◽  
Numerical Models ◽  
Load Capacity ◽  
Damage Model ◽  
Urban Region ◽  
Seismic Load ◽  
Crystalline Plasticity ◽  
Load Displacement ◽  
Cohesive Damage

In Indonesia, number of non-engineered structures have significantly been found which the houses were built by unskilled workers using masonry either unconfined or confined. The non-engineered housing units developed in urban region are also vulnerable to seismic hazard due to the use of low quality of material and constructions method. Those structures are not resistant to extreme lateral loads and their failure during an earthquake can lead to significant loss of life. This paper is concerned with the structural performance of Indonesian low-rise buildings made of masonry under lateral seismic load. Experimental testing of masonry has been carried out in Indonesia to establish the quality of materials and to provide material properties for numerical simulations. The results found that the strength of Indonesia-Bali clay brick masonry are below the minimum standard required for masonry structures built in seismic regions, being at least 50% lower than the requirement specified in British Standard and Eurocode-6 (BS EN 1996-1-1:2005). In general, structural tests under monotonic and cyclic loading have been conducted to determine the load-displacement capacity of local hand-made masonry wall panels in order to: (1) evaluate the performance of masonry structure, (2) investigate the dynamic behaviour of the structure, and (3) observe the effect of in-plane stiffness and ductility level. Detailed numerical models of the experimental specimens were simulated in Abaqus using three-dimensional solid elements. Cohesive elements were used to simulate the mortar behaviour, exhibiting cracking and the associated physical separation of the elements. A range of available material plasticity models were reviewed: Drucker-Prager, Crystalline Plasticity, and Cohesive Damage model. It was found that the combination of Crystalline Plasticity model for the brick unit and the Cohesive Damage model for the mortar is capable of simulating the experimental load-displacement behavour fairly accurately. The validated numerical models have been used to (1) predict the lateral load capacity, (2) determine the cracking load and patterns, (3) carry out a detailed parametric study by changing the geometric and material properties different to the experimental specimens. The numerical models were used to assess different strengthening measures such as using bamboo as reinforcement in the masonry walls which the performance of wall found to be better

Mode II Fracture Characterization of Pinus Pinaster Wood

2008 ◽  
Vol 587-588 ◽  
pp. 594-598
Author(s):  
Marcelo F.S.F. de Moura ◽  
M.A.L. Silva ◽  
J.J.L. Morais ◽  
A.B. de Morais ◽  
J.M.Q. Oliveira
Keyword(s):  
Crack Length ◽  
Pinus Pinaster ◽  
Process Zone ◽  
Damage Model ◽  
Crack Tip ◽  
Experimental Tests ◽  
Mode Ii ◽  
Fracture Characterization ◽  
Mode Ii Fracture ◽  
Cohesive Damage

This paper describes experimental and numerical studies on the application of the End Notched Flexure (ENF) and End Loaded Split (ELS) tests to mode II wood fracture characterization. In this context, ENF and ELS specimens were used to determine GIIc of a clear Pinus pinaster wood in the RL system, which is the most relevant for structural design. In mode II fracture tests the crack faces are in contact, thus hindering a rigorous visualization of the crack tip. This makes classic methodologies based on crack length measurement during experimental tests inadequate, since they induce significant errors on the mode II fracture properties. To overcome this experimental problem a Compliance Based Beam Method (CBBM) is used. This new data reduction scheme does not require crack length monitoring and includes the effect of the Fracture Process Zone (FPZ) ahead of crack tip. Furthermore, the clamped cross-section rotation of the ELS specimen is also taken into account. In the present work a numerical analysis considering a cohesive damage model was performed with a cohesive damage model in order to validate the application of the CBBM to the experimental results. The results confirmed the adequacy of the CBBM and the applicability of the ENF and ELS tests for mode II wood fracture characterization.

Sign in / Sign up

Export Citation Format

Share Document