Constitutive relationship of IN690 superalloy by using uniaxial compression tests

Rare Metals ◽  
2011 ◽  
Vol 30 (1) ◽  
pp. 81-86 ◽  
Author(s):  
Chaoyang Sun ◽  
Jinrong Liu ◽  
Rui Li ◽  
Qingdong Zhang ◽  
Jianxin Dong
Keyword(s):  
Uniaxial Compression ◽  
Constitutive Relationship ◽  
Compression Tests ◽  
Relationship Of

scholarly journals Compressive Test Characteristics and Constitutive Relationship of Wet Polypropylene Macrofiber-Reinforced Shotcrete

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Fenghui Li ◽  
Yunhai Cheng ◽  
Fei Wu ◽  
Chang Su ◽  
Gangwei Li
Keyword(s):  
Mechanical Response ◽  
Average Energy ◽  
Strain Curve ◽  
Peak Stress ◽  
Constitutive Relationship ◽  
Compression Tests ◽  
Response Characteristics ◽  
Test Characteristics ◽  
High Crack ◽  
Relationship Of

Shotcrete is often subject to poor ductility and cracking problems, particularly under high stresses. In order to deal with these issues, the feasibility of adding polypropylene macrofibers to shotcrete was verified. To ascertain the supporting effect, dry shotcrete, wet shotcrete, and wet polypropylene macrofiber-reinforced shotcrete (WPMS) were used as samples. Furthermore, the mechanical response characteristics thereof in uniaxial compression tests were compared and analyzed by acoustic emission (AE) monitoring. The results showed that the three materials were brittle, but the ductility, residual strength, and bearing capacity of polypropylene macrofiber-reinforced shotcrete were significantly enhanced. The energy absorption value of plain shotcrete was higher in the cracking stage, while that of polypropylene macrofiber-reinforced shotcrete was greater in the postpeak stage, which showed that the polypropylene macrofiber-reinforced shotcrete had the characteristics of a high crack-initiation strength and toughness. Besides, the energy release from fiber shotcrete occurred after the peak stress rather than near the peak stress. The average energy absorbed by polypropylene macrofiber-reinforced shotcrete was significantly higher than that in dry shotcrete and wet shotcrete, which implied that polypropylene macrofiber-reinforced shotcrete could mitigate the brittle instability of a shotcrete layer. A constitutive model of damage statistics was established based on the test data. The comparison between the experimental data and the fitting results can reflect the characteristics of the total stress-strain curve of such shotcrete. The results provide a basis for the optimization of polypropylene macrofiber-reinforced shotcrete layers.

scholarly journals Stochastic Constitutive Relationship of Self-Compacting Concrete under Uniaxial Compression

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Xiao Li ◽  
Zhi Shan ◽  
Zhiwu Yu ◽  
Jing Gao ◽  
Jianfeng Mao
Keyword(s):  
Uniaxial Compression ◽  
Practical Method ◽  
Constitutive Relationship ◽  
Experimental Investigations ◽  
Chain Model ◽  
Self Compacting Concrete ◽  
Mechanical Responses ◽  
Cyclic Compression ◽  
Proposed Model ◽  
Relationship Of

Experimental investigations on self-compacting concrete (SCC) under uniaxial monotonic and cyclic compression taking into account the stochastic constitutive relationship were reported and conducted. By introducing a practical method on plasticity characterization into the fiber bundle-plastic chain model, a new constitutive model based on the statistic damage approach for describing the stochastic mechanical responses of SCC under uniaxial compression was proposed. The comparison between the experimental results and the predictions demonstrated that the proposed model was able to characterize the salient features for SCC under both uniaxial monotonic and cyclic compression. Furthermore, the stochastic evolution (SE) of SCC under uniaxial compression and a comparison between the SCC and normally vibrated concrete (NVC) in certain aspects were analyzed and discussed; it was concluded that the stochastic constitutive relationship of SCC under compression can be understood by a media process of transition from microscale to macroscale.

scholarly journals Study on constitutive relationship of acicular wollastonite polypropylene hybrid fiber concrete under uniaxial compression

2021 ◽  
Vol 2085 (1) ◽  
pp. 012037
Author(s):  
Xu Yan ◽  
Hao Liu ◽  
Yang Liu ◽  
Jin Xie
Keyword(s):  
Uniaxial Compression ◽  
Test Data ◽  
Constitutive Relationship ◽  
Hybrid Fiber ◽  
Steel Tubes ◽  
The Press ◽  
Fiber Concrete ◽  
Relationship Of

Abstract In order to study the influence of fiber parameters on the performance of ordinary hybrid fiber concrete, the corresponding constitutive relationship of hybrid fiber concrete is proposed. The test data are obtained by adding steel tubes to increase the stiffness of the press, and the constitutive relationship of C40 hybrid fiber concrete is proposed. The constitutive relationship is polynomial in the rising section and rational in the falling section.

The Constitutive Relationship of High Strength Concrete under Uniaxial Compression

2013 ◽  
Vol 838-841 ◽  
pp. 3-6 ◽  
Author(s):  
Jin Cai Zhu ◽  
Chang Wang Yan ◽  
Shu Guang Liu
Keyword(s):  
Uniaxial Compression ◽  
High Strength Concrete ◽  
High Performance ◽  
High Performance Concrete ◽  
Constitutive Relations ◽  
High Strength ◽  
Constitutive Relationship ◽  
Strength Concrete ◽  
Relationship Of ◽  
Theoretical Results

Study of Constitutive relations of concrete based on Chinese and foreign scholars. This paper put forward constitutive equation that more close to the stress-strain data of high strength concrete under uniaxial compression, and make a comparison between the theoretical results and experimental data, and promising results were obtained. It can be used as a basis for researching of high strength and high performance concrete of other mechanical properties.

Study on Hot Deformation Behavior of Cast-and-Homogenized Superalloy GH706

2015 ◽  
Vol 816 ◽  
pp. 648-654
Author(s):  
Yan Hui Yang ◽  
Dong Liu ◽  
Jian Bing Peng ◽  
Jian Guo Wang ◽  
Guo Wei Liu ◽  
...  
Keyword(s):  
Experimental Data ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
Linear Regression Analysis ◽  
Constitutive Relationship ◽  
Strain Rates ◽  
Compression Tests ◽  
Hot Deformation Behavior ◽  
Flow Curves ◽  
Relationship Of

Hot deformation behavior of cast-and-homogenized GH706-ingot material was studied in this work. Isothermal uniaxial compression tests were performed at temperatures (°C): 990, 1020, 1050, 1080 and 1100 with strain rates (s-1): 0.01, 0.1 and 1. The stress-strain curves as well as changes in microstructures of various hot deformed specimens were analyzed. Inhomogeneous microstructures were found in the specimens and the flow curves were resulted from the comprehensive functions of microstructures change in all part of the specimens. The constitutive relationship of alloy GH706 has been established by linear regression analysis of the experimental data taken from the Arrhenius equations as a model. Then hot compression tests were carried out to estimate the allowable reductions, and 52.5% and 50.6% are suggested as the allowable reductions during cogging processing of GH706 alloy in each blow at 1110°C and 1130°C.

scholarly journals Investigation of Microcrack Propagation and Energy Evolution in Brittle Rocks Based on the Voronoi Model

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2108
Author(s):  
Guanlin Liu ◽  
Youliang Chen ◽  
Xi Du ◽  
Peng Xiao ◽  
Shaoming Liao ◽  
...  
Keyword(s):  
Uniaxial Compression ◽  
Damage Evolution ◽  
Rock Sample ◽  
Rock Fracture ◽  
Damage Threshold ◽  
Crack Development ◽  
Energy Evolution ◽  
Shear Cracks ◽  
Compression Tests ◽  
Microcrack Propagation

The cracking of rock mass under compression is the main factor causing structural failure. Therefore, it is very crucial to establish a rock damage evolution model to investigate the crack development process and reveal the failure and instability mechanism of rock under load. In this study, four different strength types of rock samples from hard to weak were selected, and the Voronoi method was used to perform and analyze uniaxial compression tests and the fracture process. The change characteristics of the number, angle, and length of cracks in the process of rock failure and instability were obtained. Three laws of crack development, damage evolution, and energy evolution were analyzed. The main conclusions are as follows. (1) The rock’s initial damage is mainly caused by tensile cracks, and the rapid growth of shear cracks after exceeding the damage threshold indicates that the rock is about to be a failure. The development of micro-cracks is mainly concentrated on the diagonal of the rock sample and gradually expands to the middle along the two ends of the diagonal. (2) The identification point of failure precursor information in Acoustic Emission (AE) can effectively provide a safety warning for the development of rock fracture. (3) The uniaxial compression damage constitutive equation of the rock sample with the crack length as the parameter is established, which can better reflect the damage evolution characteristics of the rock sample. (4) Tensile crack requires low energy consumption and energy dispersion is not concentrated. The damage is not apparent. Shear cracks are concentrated and consume a large amount of energy, resulting in strong damage and making it easy to form macro-cracks.

The Constitutive Model for High Temperature Flow Behavior of SiC/6168Al Composite

2015 ◽  
Vol 1089 ◽  
pp. 37-41
Author(s):  
Jiang Wang ◽  
Sheng Li Guo ◽  
Sheng Pu Liu ◽  
Cheng Liu ◽  
Qi Fei Zheng
Keyword(s):  
Constitutive Model ◽  
Hot Deformation ◽  
Flow Behavior ◽  
Type Equation ◽  
Strain Rate Range ◽  
Compression Tests ◽  
Stress Strain ◽  
Hollomon Parameter ◽  
Proposed Model ◽  
Relationship Of

The hot deformation behavior of SiC/6168Al composite was studied by means of hot compression tests in the temperature range of 300-450 °C and strain rate range of 0.01-10 s-1. The constitutive model was developed to predict the stress-strain curves of this composite during hot deformation. This model was established by considering the effect of the strain on material constants calculated by using the Zenter-Hollomon parameter in the hyperbolic Arrhenius-type equation. It was found that the relationship of n, α, Q, lnA and ε could be expressed by a five-order polynomial. The stress-strain curves obtained by this model showed a good agreement with experimental results. The proposed model can accurately describe the hot flow behavior of SiC/6168Al composite, and can be used to numerically analyze the hot forming processes.

scholarly journals Quantitative 3D imaging of partially saturated granular materials under uniaxial compression

2021 ◽  
Author(s):  
Marius Milatz ◽  
Nicole Hüsener ◽  
Edward Andò ◽  
Gioacchino Viggiani ◽  
Jürgen Grabe
Keyword(s):  
Granular Materials ◽  
Uniaxial Compression ◽  
Water Clusters ◽  
Local Strain ◽  
Confining Pressure ◽  
Mechanical Effect ◽  
Compression Tests ◽  
Initial Water ◽  
Interfacial Areas ◽  
Membrane Effects

AbstractGauging the mechanical effect of partial saturation in granular materials is experimentally challenging due to the very low suctions resulting from large pores. To this end, a uniaxial (zero radial stress) compression test may be preferable to a triaxial one where confining pressure and membrane effects may erase the contribution of this small suction; however, volume changes are challenging to measure. This work resolves this limitation by using X-ray imaging during in situ uniaxial compression tests on Hamburg Sand and glass beads at three different initial water contents, allowing a suction-dependent dilation to be brought to the light. The acquired tomography volumes also allow the development of air–water and solid–water interfacial areas, water clusters and local strain fields to be measured at the grain scale. These measurements are used to characterise pertinent micro-scale quantities during shearing and to relate them to the measured macroscopic response. The new and well-controlled data acquired during this experimental campaign are hopefully a useful contribution to the modelling efforts—to this end they are shared with the community.

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