Three Parameters Damage Model for Concrete

2009 ◽  
Author(s):  
A.R. Khan ◽  
A.H. Al-Gadhib ◽  
M.H. Baluch
Keyword(s):  
Damage Model

Why is it necessary to use a damage model to simulate the mechanical behavior of concrete under drying and leaching?

2010 ◽  
Vol 14 (6-7) ◽  
pp. 923-935
Author(s):  
Thomas Rougelot ◽  
Cheng Peng ◽  
Nicolas Burlion ◽  
Dominique Bernard
Keyword(s):  
Mechanical Behavior ◽  
Damage Model

scholarly journals A Novel Damage Model for Strata Layers and Coal Mass

Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1928 ◽  
Author(s):  
Faham Tahmasebinia ◽  
Chengguo Zhang ◽  
Ismet Canbulat ◽  
Samad Sepasgozar ◽  
Serkan Saydam
Keyword(s):  
Constitutive Model ◽  
Strain Energy ◽  
Damage Model ◽  
Rock Joint ◽  
Coal Mass ◽  
Stored Energy ◽  
Rock Interaction ◽  
Geological Factors ◽  
Coal Rock ◽  
Joint Quality

Coal burst occurrences are affected by a range of mining and geological factors. Excessive slipping between the strata layers may release a considerable amount of strain energy, which can be destructive. A competent strata is also more vulnerable to riveting a large amount of strain energy. If the stored energy in the rigid roof reaches a certain level, it will be released suddenly which can create a serious dynamic reaction leading to coal burst incidents. In this paper, a new damage model based on the modified thermomechanical continuum constitutive model in coal mass and the contact layers between the rock and coal mass is proposed. The original continuum constitutive model was initially developed for the cemented granular materials. The application of the modified continuum constitutive model is the key aspect to understand the momentum energy between the coal–rock interactions. The transformed energy between the coal mass and different strata layers will be analytically demonstrated as a function of the rock/joint quality interaction conditions. The failure and post failure in the coal mass and coal–rock joint interaction will be classified by the coal mass crushing, coal–rock interaction damage and fragment reorganisation. The outcomes of this paper will help to forecast the possibility of the coal burst occurrence based on the interaction between the coal mass and the strata layers in a coal mine.

Ductile Crack Extension Analysis for X80 Bending Deformation Using Damage-Based Model

2014 ◽  
Author(s):  
Satoshi Igi ◽  
Mitsuru Ohata ◽  
Takahiro Sakimoto ◽  
Kenji Oi ◽  
Joe Kondo
Keyword(s):  
Plastic Strain ◽  
Simulation Model ◽  
Crack Growth ◽  
Crack Extension ◽  
Damage Model ◽  
Stress Triaxiality ◽  
Crack Growth Behavior ◽  
Ductile Crack ◽  
Ductile Crack Growth ◽  
Notch Tip

This paper presents experimental and analytical results focusing on the strain limit of X80 linepipe. Ductile crack growth behavior from a girth weld notch is simulated by FE analysis based on a proposed damage model and is compared with the experimental results. The simulation model for ductile crack growth accompanied by penetration through the wall thickness consists of two criteria. One is a criterion for ductile crack initiation from the notch-tip, which is described by the plastic strain at the notch tip, because the onset of ductile cracking can be expressed by constant plastic strain independent of the shape and size of the components and the loading mode. The other is a damage-based criterion for simulating ductile crack extension associated with damage evolution influenced by plastic strain in accordance with the stress triaxiality ahead of the extending crack tip. The proposed simulation model is applicable to prediction of ductile crack growth behaviors from a circumferentially-notched girth welded pipe with high internal pressure, which is subjected to tensile loading or bending (post-buckling) deformation.

scholarly journals Effect of Shuangdan Mingmu capsule, a Chinese herbal formula, on oxidative stress-induced apoptosis of pericytes through PARP/GAPDH pathway

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Fujiao Nie ◽  
Jiazhao Yan ◽  
Yanjun Ling ◽  
Zhengrong Liu ◽  
Chaojun Fu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Nitric Oxide ◽  
Oxidative Damage ◽  
Damage Model ◽  
B Cell Lymphoma ◽  
Cell Counting ◽  
Network Pharmacology ◽  
Diabetic Patients ◽  
Induced Apoptosis

Abstract Background Diabetic retinopathy (DR) has become a worldwide concern because of the rising prevalence rate of diabetes mellitus (DM). Despite much energy has been committed to DR research, it remains a difficulty for diabetic patients all over the world. Since apoptosis of retinal microvascular pericytes (RMPs) is the early characteristic of DR, this study aimed to reveal the mechanism of Shuangdan Mingmu (SDMM) capsule, a Chinese patent medicine, on oxidative stress-induced apoptosis of pericytes implicated with poly (ADP-ribose) polymerase (PARP) / glyceraldehyde 3-phosphate dehydrogenase (GAPDH) pathway. Methods Network pharmacology approach was performed to predict biofunction of components of SDMM capsule dissolved in plasma on DR. Both PARP1 and GAPDH were found involved in the hub network of protein-protein interaction (PPI) of potential targets and were found to take part in many bioprocesses, including responding to the regulation of reactive oxygen species (ROS) metabolic process, apoptotic signaling pathway, and response to oxygen levels through enrichment analysis. Therefore, in vitro research was carried out to validate the prediction. Human RMPs cultured with media containing 0.5 mM hydrogen oxide (H2O2) for 4 h was performed as an oxidative-damage model. Different concentrations of SDMM capsule, PARP1 inhibitor, PARP1 activation, and GAPDH inhibitor were used to intervene the oxidative-damage model with N-Acetyl-L-cysteine (NAC) as a contrast. Flow cytometry was performed to determine the apoptosis rate of cells and the expression of ROS. Cell counting kit 8 (CCK8) was used to determine the activity of pericytes. Moreover, nitric oxide (NO) concentration of cells supernatant and expression of endothelial nitric oxide synthase (eNOS), superoxide dismutase (SOD), B cell lymphoma 2 (BCL2), vascular endothelial growth factor (VEGF), endothelin 1 (ET1), PARP1, and GAPDH were tested through RT-qPCR, western blot (WB), or immunocytochemistry (ICC). Results Overproduction of ROS, high apoptotic rate, and attenuated activity of pericytes were observed after cells were incubated with media containing 0.5 mM H2O2. Moreover, downregulation of SOD, NO, BCL2, and GAPDH, and upregulation of VEGFA, ET1, and PARP1 were discovered after cells were exposed to 0.5 mM H2O2 in this study, which could be improved by PARP1 inhibitor and SDMM capsule in a dose-dependent way, whereas worsened by PARP1 activation and GAPDH inhibitor. Conclusions SDMM capsule may attenuate oxidative stress-induced apoptosis of pericytes through downregulating PARP expression and upregulating GAPDH expression.

Progressive damage characteristics of screwed single-lap CFRPI-metal joint subjected to tensile loading at RT and 350°C

2021 ◽  
pp. 002199832098559
Author(s):  
Yun-Tao Zhu ◽  
Jun-Jiang Xiong ◽  
Chu-Yang Luo ◽  
Yi-Sen Du
Keyword(s):  
Damage Model ◽  
Tensile Loading ◽  
Tensile Tests ◽  
Displacement Curve ◽  
Progressive Damage ◽  
Damage Characteristics ◽  
Metal Joint ◽  
Static Tensile ◽  
Strength And Stiffness ◽  
Progressive Damage Model

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.

Statistical micromechanical damage model for SH-SFRC under tensile load considering the interfacial slip-softening and matrix spalling effects

2021 ◽  
pp. 105678952110112
Author(s):  
Hehua Zhu ◽  
Xiangyang Wei ◽  
J Woody Ju ◽  
Qing Chen ◽  
Zhiguo Yan ◽  
...  
Keyword(s):  
Strain Hardening ◽  
Steel Fiber ◽  
Damage Model ◽  
Fiber Reinforced Concrete ◽  
Uniaxial Tensile ◽  
Interfacial Slip ◽  
Fiber Reinforced ◽  
Micromechanical Damage ◽  
The Impact ◽  
Micromechanical Damage Model

Strain hardening behavior can be observed in steel fiber reinforced concretes under tensile loads. In this paper, a statistical micromechanical damage framework is presented for the strain hardening steel fiber reinforced concrete (SH-SFRC) considering the interfacial slip-softening and matrix spalling effects. With a linear slip-softening interface law, an analytical model is developed for the single steel fiber pullout behavior. The crack bridging effects are reached by averaging the contribution of the fibers with different inclined angles. Afterwards, the traditional snubbing factor is modified by considering the fiber snubbing and the matrix spalling effects. By adopting the Weibull distribution, a statistical micromechanical damage model is established with the fracture mechanics based cracking criteria and the stress transfer distance. The comparison with the experimental results demonstrates that the proposed framework is capable of reproducing the SH-SFRC’s uniaxial tensile behavior well. Moreover, the impact of the interfacial slip-softening and matrix spalling effects are further discussed with the presented framework.

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