Experimental and numerical investigation of ductile fracture using GTN damage model on in-situ tensile tests

2019 ◽  
Vol 164 ◽  
pp. 105170 ◽  
Author(s):  
H. Gholipour ◽  
F.R. Biglari ◽  
K. Nikbin
2021 ◽  
Vol 40 (1) ◽  
pp. 310-324
Author(s):  
Ying Tong ◽  
Jiang Zhao ◽  
Guo-zheng Quan

Abstract Understanding the damage evolution of alloys during a plastic deformation process is significant to the structural design of components and accident prevention. In order to visualize the damage evolution in the plastic deformation of Ti–3Al–2Mo–2Zr alloy, a series of uniaxial tensile experiments for this alloy were carried out under the strain rates of 0.1–10 s−1 at room temperature, and the stress–strain curves were achieved. On the other hand, the finite element (FE) models of these uniaxial tensile processes were established. A microvoids proliferation model, Gurson–Tvergaard–Needleman (GTN) damage model, was implanted into the uniaxial tensile models, and the simulated stress–strain curves corresponding to different GTN parameter combinations were obtained. Based on the simulated and experimental stress–strain curves, the GTN parameters of this alloy were solved by response surface methodology (RSM). The solved GTN parameters suggest that higher strain rate can enhance the proliferation and coalescence of microvoids. Furthermore, the uniaxial tensile tests over different strain rates were simulated using the solved GTN parameters. Then, the damage processes were visualized and evaluated. The result shows that the degradation speed of this alloy is slow at the initial stage of the tensile deformation and then accelerates once the voids volume fraction reaches a critical value.


2021 ◽  
pp. 002199832098559
Author(s):  
Yun-Tao Zhu ◽  
Jun-Jiang Xiong ◽  
Chu-Yang Luo ◽  
Yi-Sen Du

This paper outlines progressive damage characteristics of screwed single-lap CFRPI-metal joints subjected to tensile loading at RT (room temperature) and 350°C. Quasi-static tensile tests were performed on screwed single-lap CCF300/AC721-30CrMnSiA joint at RT and 350°C, and the load versus displacement curve, strength and stiffness of joint were gauged and discussed. With due consideration of thermal-mechanical interaction and complex failure mechanism, a modified progressive damage model (PDM) based on the mixed failure criterion was devised to simulate progressive damage characteristics of screwed single-lap CCF300/AC721-30CrMnSiA joint, and simulations correlate well with experiments. By using the PDM, the effects of geometry dimensions on mechanical characteristics of screwed single-lap CCF300/AC721-30CrMnSiA joint were analyzed and discussed.


1986 ◽  
Vol 25 (3) ◽  
pp. 377-384 ◽  
Author(s):  
Wei Hua Tai ◽  
Bing Xian Yang

2013 ◽  
Vol 351-352 ◽  
pp. 1552-1557
Author(s):  
Da Guo Wang ◽  
Zhi Xiu Wang ◽  
Bing Xu

Based on micromechanics, an elastic-plastic-brittle damage model of concrete beam reinforced with stick steel is proposed by considering the aggregate gradation curve algorithms and the heterogeneity. In the model, the concrete beam reinforced with stick steel is taken as a five-phase composite material that consists of the mortar matrix, coarse aggregate, bonds between mortar and aggregate, steel plate, and the adhesive layer between steel plate and concrete beam. Through the numerical investigation on shear failure of concrete beam reinforced with stick steel under external force, the results show that the model can clearly simulate microscopic plastic yield, and the initiation and extension of crack. The strength of the steel plate is relatively stronger, so it cant enhance the shear capability of the each side of the beam and the concrete beam bears the larger shear stress, which results that a large number of elements, from the supports to the load points, begin to yield. When the strain of the elements exceeds the yield strength, the elements will produce failure until the failure of the whole specimen. The final failure mode of concrete beam reinforced with stick steel is the shear failure.


2009 ◽  
Vol 65 ◽  
pp. 19-31
Author(s):  
Ruben Cuamatzi-Melendez ◽  
J.R. Yates

Little work has been published concerning the transferability of Gurson’s ductile damage model parameters in specimens tested at different strain rates and in the rolling direction of a Grade A ship plate steel. In order to investigate the transferability of the damage model parameters of Gurson’s model, tensile specimens with different constraint level and impact Charpy specimens were simulated to investigate the effect of the strain rate on the damage model parameters of Gurson model. The simulations were performed with the finite element program ABAQUS Explicit [1]. ABAQUS Explicit is ideally suited for the solution of complex nonlinear dynamic and quasi–static problems [2], especially those involving impact and other highly discontinuous events. ABAQUS Explicit supports not only stress–displacement analyses but also fully coupled transient dynamic temperature, displacement, acoustic and coupled acoustic–structural analyses. This makes the program very suitable for modelling fracture initiation and propagation. In ABAQUS Explicit, the element deletion technique is provided, so the damaged or dead elements are removed from the analysis once the failure criterion is locally reached. This simulates crack growth through the microstructure. It was found that the variation of the strain rate affects slightly the value of the damage model parameters of Gurson model.


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