Experimental Study on Fracture Parameter of Three-Point Bending Beam Based on Smart Properties of CFRC

2008 ◽  
Author(s):  
Dian-jun Zhang ◽  
Shi-lang Xu
2021 ◽  
Vol 900 ◽  
pp. 9-15
Author(s):  
Mouad Bellahkim ◽  
Youssef Benbouras ◽  
Aziz Maziri ◽  
El Hassan Mallil ◽  
Jamal Echaabi

In this work, an attempt has been made to study the experimental of behavior for carbon/epoxy woven laminates under a three-point bending test by varying the support span and the geometrical dimensions of the specimens. Two principles stacking sequences are studied ([45 / 0]2s & [90 / 0]6 ) to observe the effect of the layer orientation in the failure modes. This study has allowed us to confirm the relationship between the bending behavior of the specimens and the span-to-thickness ratio (l/h). Finally, a digital microscope was selected in order to characterize the succession of the failure and the failure modes, mainly the delamination damage.


2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Qifeng Guo ◽  
Xinghui Wu ◽  
Meifeng Cai ◽  
Shengjun Miao

To investigate the effects of offset notch on the fracture properties of rock beam under bending load, granite beam specimens with “one single offset notch” and “central and offset double notches” are made. A series of three-point bending beam tests on the specimens are carried out by controlling the displacement rate of central notch. The whole load-displacement (P-CMOD) curves are obtained. Experimental results show that the larger the distance between the offset notch and beam central is, the larger are the peak load and nominal strength of the specimen. The peak load and nominal strength for the “central and offset double notches” specimens are both larger than those for the “single central notch” specimen. A fracture model considering the effect of offset notch is developed, and the relationship between the offset notch parameter, tensile strength, and fracture toughness is established.


2019 ◽  
Vol 286 ◽  
pp. 02007
Author(s):  
Y. Benbouras ◽  
M. Bellahkim ◽  
A. Maziri ◽  
E. Mallil ◽  
J. Echaabi

The application of failure criteria are difficult partly because they are too various and must be validated by biaxial tests, which are expensive to be achieved. In this work, an analytical modeling based on a software program has been elaborated for application of the most general failure criteria and prediction of successive failure. Finally, the results obtained by this analytical modeling show a good correlation with those carried out by experimental study.


2013 ◽  
Vol 577-578 ◽  
pp. 205-208
Author(s):  
Sara Korte ◽  
Veerle Boel ◽  
Wouter de Corte ◽  
Geert de Schutter

Vibrated concrete (VC) and self-compacting concrete (SCC) have a substantially different composition, resulting in dissimilar mechanical properties regarding cracking behaviour. The critical value of the mode I stress-intensity factor KICis an appropriate fracture parameter for evaluating fracture toughness and can be obtained from three-point bending tests (3PBT) on small, notched specimens. Subsequent determination of the energy release rate thus allows to examine the crack propagation and fracture process of both concrete types. This paper describes the results of such 3PBTs on samples, made from VC and SCC. Evaluation of the cracking behaviour, derived from these results, reveals remarkable differences.


2018 ◽  
Vol 18 (08) ◽  
pp. 1840024
Author(s):  
MONAN WANG ◽  
RONGPENG LI ◽  
JUNTONG JING

Living body or corpse could be replaced with the virtual human tissue model for biomechanical experimental study, which effectively avoids the non-reusability, great social controversy, huge costs and difficulty in extracting parameters, and finally, the accurate analysis results are obtained. Unlike the previous lower limb models, the finite element models of hip and thigh were established based on the concept of muscle group in this paper. The cortical bones of hip bone and femur were set as *MAT_PIECEWISE_LINEAR_ PLASTICITY. The material of cancellous bone was set as *MAT_ELASTIC_PLASTIC_ WITH_DAMAGE_FAILURE. The material of articular cartilage was set as *MAT_ISOTROPIC_ELASTIC. The materials of muscle and fat were set as *MAT_VISCOELASTIC. The accuracy of the finite element model was verified by dynamic three-point bending experiment of the thighs. Mechanical simulation was carried out to the stump-prosthetic socket and the comfort of socks by the established model. The simulation results were all between the upper and lower bounds of the experimental results in the dynamic three-point bending experiment of the thighs where the loads were separately applied to one-third of the distal end of thighs and the middle part of thighs. The simulation results of the stump-prosthetic socket example show that the optimal elastic modulus of silicone pad is 2.5[Formula: see text]MPa. Simulation results of socks comfort show that the distribution of stress and deformation of the anterior and posterior thighs is different when the human lower limbs are in stockings. The established simulation model meets the accuracy requirement and can replace the living body or corpse to carry out biomechanical experimental study. The finite element simulation results converge, and the time to complete a finite element calculation is less than or equal to 10[Formula: see text]min.


2019 ◽  
Vol 28 (2) ◽  
pp. 119-139
Author(s):  
Youssef Benbouras ◽  
Mouad Bellahkim ◽  
Aziz Maziri ◽  
Elhassan Mallil ◽  
Jamal Echaabi

The application of modeling theories and the choice of failure criteria are difficult in part because they are too varied and must be validated by biaxial tests, which are expensive to be performed. This article is devoted to the nonlinear modeling and failure criteria which are employed in the design and analysis of anisotropic materials. Indeed, in this work, a study of the macroscopic and microscopic behavior of a graphite epoxy under a three-point bending test is conducted, and the successive failures are also predicted. Experimentally, the damage progression and the effect of geometrical parameters are followed and identified in detail. The analytical modeling is based on a recently developed approximation for isotropic materials. This approximation is also valid for the studied quasi-isotropic laminated composite. A software program has been elaborated for the application of the most general failure criteria. The results obtained by this analytical modeling show a good correlation with those of the experimental study.


2012 ◽  
Vol 226-228 ◽  
pp. 937-941 ◽  
Author(s):  
Shao Wei Hu ◽  
Zheng Xiang Mi ◽  
Jun Lu

In order to study the influence of the crack-depth ratio on reinforced concrete fracture parameters and the resistance of the reinforcing bar to crack propagation in concrete, the fracture tests were carried on by using four groups three-point bending specimens with initial crack-depth ratios of 0.2, 0.3, 0.4 and 0.5 in this paper. An analytical model was presented to calculate fracture toughness of reinforced concrete by analyzing crack propagation process of the three-point bending beams. The formula of calculating effective crack length of reinforced concrete was established. The research results show that the double-K criterion can be used for describing crack propagation process of reinforced concrete by introducing fracture toughness, which is suitable for reinforced concrete. Initiation fracture toughness and unstable fracture toughness of reinforced concrete slowly increase with the increase of crack-depth ratio, which is different from the properties of ordinary concrete. The reinforced can improve the ductility of concrete obviously and inhibit the rate of crack propagation well.


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