Mechanical property deterioration characteristics and a new constitutive model for rocks subjected to freeze-thaw weathering process

2021 ◽  
Vol 140 ◽  
pp. 104642
Author(s):  
Feng Gao ◽  
Xin Xiong ◽  
Chaoshui Xu ◽  
Keping Zhou
Keyword(s):  
Mechanical Property ◽  
Constitutive Model ◽  
Freeze Thaw ◽  
Deterioration Characteristics ◽  
Weathering Process

scholarly journals A semi-empirical elasto-plastic constitutive model for coarse-grained materials that incorporates the effects of freeze-thaw cycles

2020 ◽  
Vol 24 ◽  
pp. 100373
Author(s):  
Shuang Tian ◽  
Buddhima Indraratna ◽  
Liang Tang ◽  
Yujie Qi ◽  
Xianzhang Ling
Keyword(s):  
Constitutive Model ◽  
Coarse Grained ◽  
Freeze Thaw ◽  
Semi Empirical

Study on the Constitutive Model of the ARB Specimen and Simulation for ARB Process

2010 ◽  
Vol 42 ◽  
pp. 391-395
Author(s):  
Zhong Wu ◽  
Li Li Liu ◽  
Guo Zhi Zhang ◽  
Jun Jie Xi
Keyword(s):  
Mechanical Property ◽  
Constitutive Model ◽  
Simulation Method ◽  
Strain Ratio ◽  
Strain Gradient Theory ◽  
Gradient Theory ◽  
Analysis Method ◽  
Roll Bonding ◽  
Element Simulation ◽  
Temperature Strain

The simulation method for ARB(accumulative roll bonding) and the constitutive model of the ARB specimen were studied. Based on the ZA(Zerilli-Armstrong) model, with MSG(mechanism-based strain gradient) theory and Hall-petch principle, considering its temperature, strain ratio and the effect of the texture variation to the mechanical property, its dynamic constitutive model was established, and verified through the experiment. Moreover, the finite element simulation method for ARB process based on the dynamic constitutive model established was proposed and verified through the experiment. The study in the paper provides analysis method and theory foundation for ARB

Study on Non-Local Damage Constitutive Model of Concrete under Freeze-Thaw Action

2010 ◽  
Vol 452-453 ◽  
pp. 133-136 ◽  
Author(s):  
Zong Min Liu ◽  
Ji Ze Mao ◽  
Hai Yan Song
Keyword(s):  
Constitutive Model ◽  
Internal State ◽  
Constitutive Relations ◽  
Irreversible Thermodynamics ◽  
Local Damage ◽  
Variable Theory ◽  
Freeze Thaw ◽  
Adjacent Point ◽  
Damage Constitutive Model ◽  
Non Local

Concrete is multi-phase composites. Due to the inhomogeneity of mechanical properties and complexity of physical properties, constitutive relations of concrete are more complicated. Starting from irreversible thermodynamics theory, internal state variable theory and nonlocal field theory, non-local damage constitutive model of concrete under freeze-thaw action is established in this paper. In the model, non-local influence functions are discussed which are used to describe interplay of damage between adjacent point.

scholarly journals A Damage Constitutive Model of Rock Subjected to Freeze-Thaw Cycles Based on Lognormal Distribution

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Hang Lin ◽  
Linyuan Liang ◽  
Yifan Chen ◽  
Rihong Cao
Keyword(s):  
Mechanical Properties ◽  
Constitutive Model ◽  
Lognormal Distribution ◽  
Constitutive Models ◽  
Strain Curve ◽  
Statistical Distribution ◽  
Freeze Thaw ◽  
Accurate Quantitative Analysis ◽  
Distribution Parameters ◽  
Damage Constitutive Model

The constitutive model of rock is closely connected with the mechanical properties of rock. To achieve a more accurate quantitative analysis of the mechanical properties of rock after the action of freeze-thaw cycles, it is necessary to establish the constitutive models of rock subjected to freeze-thaw cycles from the view of rock damage. Based on the assumption of rock couple damage, this study established a statistical damage constitutive model of rock subjected to freeze-thaw cycles by combining the lognormal distribution, which is commonly used in engineering reliability analysis, and the strain strength theory. Then, the coordinates and derivative at the peak of the stress-strain curve of the rock after the action of freeze-thaw cycles were obtained through experiments to solve the statistical distribution parameters με and S of the model, whereafter, the theoretical curves by the established model were compared with the experimental curves to verify the validity of it, which shows a great agreement. Finally, the sensitivity analysis of the statistical distribution parameters was implemented. The results indicate that με reflects the strength of the rock, which shows a positive relation, and S stands for the brittleness of the rock, which shows a negative relation.

scholarly journals Deterioration characteristics of cement-improved loess under dry–wet and freeze–thaw cycles

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0253199
Author(s):  
Ying-jun Jiang ◽  
Chen-yang Ni ◽  
Hong-wei Sha ◽  
Zong-hua Li ◽  
Lu-yao Cai
Keyword(s):  
Static Pressure ◽  
Vertical Vibration ◽  
Strength Degradation ◽  
Freeze Thaw ◽  
Molding Method ◽  
Pressure Method ◽  
Joint Influence ◽  
Influence Of Water ◽  
Degradation Effect ◽  
Deterioration Characteristics

The effects of cement dosage, compaction coefficient, molding method (vertical vibration method and static pressure method), and dry–wet and freeze–thaw cycles on the mechanical strength of cement-improved loess (CIL) were studied to reveal its strength degradation law under dry–wet and freeze–thaw cycles. Results show that when using the vertical vibration molding method, the strength degradation effect of CIL can be improved by increasing the cement dosage and compaction coefficient; however, it is not obvious. Under the action of dry–wet cycle, damages, such as voids and cracks of CIL, develop continuously. Further, the strength deteriorates continuously and does not decrease after more than 15 dry–wet cycles. Therefore, the dry–wet cycle degradation system is selected by considering the most unfavorable conditions. In the process of freeze–thaw alternation, the pores and fissures of CIL develop and evolve continuously and the strength deteriorates continuously under the joint influence of water and low temperature. The strength tends to become stable after more than 12 freeze–thaw cycles. According to the safety principle, the deterioration coefficient of the freeze–thaw cycles is 0.3.

Uniaxial Compression Fractal Damage Constitutive Model of Rock Subjected to Freezing and Thawing

2020 ◽  
Author(s):  
Shengtao Zhou ◽  
Nan Jiang ◽  
Xuedong Luo ◽  
Wen Fang ◽  
Xu He
Keyword(s):  
Mechanical Properties ◽  
Constitutive Model ◽  
Uniaxial Compression ◽  
Residual Strength ◽  
Structural Damage ◽  
Compression Fracture ◽  
Peak Strain ◽  
Freeze Thaw ◽  
Deformation Stage ◽  
Damage Constitutive Model

Mechanical properties of the rock in the cold regions are often affected by freeze-thaw cycles and loads. It is of great theoretical significance and engineering value to establish a uniaxial compression damage constitutive model of the rock under freeze-thaw cycles that can reflect the relationship between macroscopic and mesoscopic structural damage. In this paper, macroscopic and mesoscopic methods are combined with statistical methods to quantitatively analyze the damage degree of rock under freeze-thaw cycles and loads. Combined with the fractal features of the macroscopic image of the section, a fractal damage constitutive model considering the residual strength of rock is established. In addition, the model is subsequently verified by the experiment. The experiment shows that the mechanical properties of rocks subjected to freeze-thaw cycles and loads are determined by freeze-thaw damage variables, load damage variables, and their coupling effects. As the number of freeze-thaw cycles increases, the uniaxial compressive strength and elastic modulus of rocks decrease, and peak strain increases. By using the fractal dimension of the compression fracture surface as a bridge considering the residual strength of the rock, the constitutive model can better reflect the compaction stage, elastic deformation stage and plastic deformation stage of the uniaxial compression process of the freeze-thaw rocks.

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