Experimental study on three-point-bending characteristics of hard and soft rock-like materials under different loading rates

2021 ◽  
Vol 14 (18) ◽  
Author(s):  
Da Huang ◽  
Yang Liu ◽  
Yunyun Yang ◽  
Zhao Li ◽  
Qiujie Meng
Author(s):  
Nguyen Trung Hieu ◽  
Nguyen Van Tuan

The elasto-plastic characteristics of plain concrete are inevitably affected by the loading rate. This paper presents an experimental investigation on the effect of loading rate on flexural behavior of concrete and reinforced concrete (RC) beams, which was carried out with Walter+bai electro-hydraulic servo system. Three-point bending tests on 100 × 100 × 400 mm prismatic concrete samples and 80 × 120 × 1100 mm RC beams with different displacement controlled loading rates of 0.01 mm/min, 0.1 mm/min, and 3 mm/min were imposed. Based on the test results, the effects of loading rates on the load-displacement curve, cracking, and ultimate load-carrying capacities of RC beams were evaluated.


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.


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.


2016 ◽  
Vol 145 ◽  
pp. 68-79 ◽  
Author(s):  
Mingxia Yao ◽  
Deju Zhu ◽  
Yiming Yao ◽  
Huaian Zhang ◽  
Barzin Mobasher

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