scholarly journals Numerical Simulation of Static Stress-Strain Relationship and Failure Mode for Freeze-Thaw Concrete

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Xiaolin Yang ◽  
Genhui Wang ◽  
Hongzhao Li ◽  
Jiang Fan
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Uniaxial Compression ◽  
Strain Curve ◽  
Stress And Strain ◽  
Uniaxial Compression Test ◽  
Stress Strain ◽  
Element Analysis ◽  
Freeze Thaw ◽  
Thaw Cycle

To analyze the causes of failure of cubic concrete test specimens under quasistatic axial compression, microtests and finite element numerical simulation of C40 cubic concrete test specimens were conducted without the freeze-thaw cycle and with 50 freeze-thaw cycles. Based on the analysis of the microstructure of concrete, the variation law of the full curve of stress and strain was analyzed by the uniaxial compression test and the splitting tensile test of concrete. The results show that freeze-thaw damage is mainly caused by the cyclic reciprocating stress of the micropore structure inside the concrete. The peak stress of concrete uniaxial compression and splitting tensile strength gradually decrease with the number of freeze-thaw cycles; the full stress-strain curve tends to shift downward and to the right. Finite element analysis shows that under the quasistatic uniaxial compression loading condition, the stress and strain fields in the test specimens are symmetrically distributed but nonuniform. The plastic deformation of the concrete weakens the nonuniformity of the stress distribution and is closer to the experimental failure morphology.

Determination of sealing pressure in hyperelastic O-ring with different hardness using numerical method

2018 ◽  
Vol 51 (7-8) ◽  
pp. 684-697 ◽  
Author(s):  
T Sukumar ◽  
BR Ramesh Bapu ◽  
B Durga Prasad
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Uniaxial Compression ◽  
Compression Test ◽  
Material Parameter ◽  
Uniaxial Compression Test ◽  
Stress Strain ◽  
Element Analysis ◽  
Strain Data ◽  
Sealing Pressure

In automotive industries, leakage is one of the major problem reducing the efficiency in hydraulic and pneumatic system. The leakage in a device can be identified only during the physical test, once after the product is developed, leading to increased development time and cost. The leakage is purely based on the type of sealing element (O-rings) and sealing pressure. Since the sealing elements are hyperelastic and exhibit highly nonlinear behavior, there is no standard formulation available to predict the sealing pressure. It can be predicted using finite element analysis (FEA) in the design stage itself. One of the main inputs for the finite element analysis is the exact material parameter of the sealing element. This article aims at determining the sealing element material parameter using stress–strain data generated from uniaxial compression test and sealing pressure considering different hardness using finite element analysis. To generate the stress–strain data, compression force is applied on the test specimen at the rate of 12 mm/min and compressed up to 25% of its initial height with help of uniaxial compression test machine as per ASTM D 575. In this article, O-ring is considered as sealing element with hardness ranging from 40 IRHD to 90 IRHD.

4H1 Finite element analysis of spine cage in the uniaxial compression test

2013 ◽  
Vol 2013 (0) ◽  
pp. 261-262
Author(s):  
Takako OSAWA ◽  
Shigeaki MORIYAMA ◽  
Tomoyo YUTANI ◽  
Naoyuki NISHIMURA ◽  
Yuki USUI ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Uniaxial Compression ◽  
Compression Test ◽  
Uniaxial Compression Test ◽  
Element Analysis

Numerical Simulation of Stress and Deformation on Heat Transfer

2011 ◽  
Vol 422 ◽  
pp. 842-845
Author(s):  
Xue Ping Wang ◽  
Ying Zhang ◽  
Pan Li ◽  
Zhen Wei Zhang
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Heat Exchange ◽  
Structure Design ◽  
Stress And Strain ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Stress And Deformation

This paper primarily simulates the heat exchange part’s stress and strain situation under the load of temperature and gravity and their coupling impact aiming at obtaining the stress and deformation distribution. The authors took advantage of the method of the finite element analysis to study the stress and strain situation. Through the analysis, each part of the transfer’s stress and strain can be calculated. The conclusion of this paper provides the basis for the further enhancement of the machine life and optimization of the structure design.

scholarly journals Three-Dimensional Reconstruction and Numerical Simulation Analysis of Acid-Corroded Sandstone Based on CT

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Zizhen Miao ◽  
Shuguang Li ◽  
Jiangsheng Xie ◽  
Runke Huo ◽  
Fan Ding ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Uniaxial Compression ◽  
Damage Evolution ◽  
Simulation Analysis ◽  
Acid Corrosion ◽  
Three Dimensional ◽  
Strain Curve ◽  
Uniaxial Compression Test ◽  
Evolution Law ◽  
Simulation Results

Due to its unique technological characteristics, coal mining and production often encounter an acid corrosion environment caused by acid gases. Acid erosion and a series of chemical reactions caused by it often led to the deterioration of coal, rock, support structure, etc. and induced serious safety accidents. To further explore the macro-mesoscopic damage evolution law and failure mechanisms of rock masses under corrosion conditions through numerical simulation, a zonal refined numerical model that can reflect the acid corrosion characteristics of sandstone is established based on CT and digital image processing (DIP). The uniaxial compression test of corroded sandstone is simulated by ABAQUS software. Comparing the numerical simulation results with the physical experiment results, we found that the three-dimensional finite element model based on CT scanning technology can genuinely reflect sandstone’s corrosion characteristic. The numerical simulation results of the stress-strain curve and macroscopic failure mode of the acid-corroded sandstone are in good agreement with the experimental results, which provides a useful method for further studying the damage evolution mechanism of the acid-corroded rock mass. Furthermore, the deformation and damage evolution law of the corroded sandstone under uniaxial compression is qualitatively analyzed based on the numerical simulation. The results show that the rock sample’s axial displacement decreases gradually from top to bottom under the axial load, and the vertical variation is relatively uniform. In contrast, the rock sample’s removal gradually increases with the increase of axial pressure, and the growth presents a certain degree of nonuniformity in the vertical. The acid-etched rock sample’s damage starts from both the end and the middle; it first appears in the corroded area. Moreover, with the displacement load increase, it gradually develops and is merged in the middle of the rock sample and forms macroscopic damage.

scholarly journals Identification of Initial Crack and Fracture Development Monitoring under Uniaxial Compression of Coal with High Bump Proneness

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Zuoqing Bi ◽  
Han Liang ◽  
Qianjia Hui
Keyword(s):  
Rock Burst ◽  
Uniaxial Compression ◽  
Failure Process ◽  
Strain Curve ◽  
Initial Crack ◽  
Internal Crack ◽  
Uniaxial Compression Test ◽  
Stress Strain ◽  
Crack Distribution ◽  
Fracture Development

The rock burst proneness of coal is closely related to the coal mass structure. Therefore, the initial crack distribution of high burst proneness coal, its fracture development, and failure process under loading conditions are of great significance for the prediction of rock burst. In this study, high burst proneness coal is used to prepare experiment samples. The surface cracks of the samples are identified and recorded. The internal crack of the sample is detected by nuclear magnetic resonance (NMR) technology to determine the crack ratio of each sample. Then, 3D-CAD technology is used to restore the initial crack of the samples. Uniaxial compression test is carried out, and AE properties are recorded in the test. The stress-strain curve, the distribution of the fractural points within the sample at different stress states, and the relationship between ring count and stress are obtained. Results show that the stress-strain curves of high burst proneness coal are almost linear, to which the stress-ring count curves are similar. The distributions of fractural points in different bearing states show that the fracture points emerge in the later load stage and finally penetrate to form macrofracture, resulting in sample failure. This study reveals the initial crack distribution of coal with high burst proneness and the fracture development under bearing conditions, which provides a theoretical basis for the prediction technology of rock burst and technical support for the research of coal structure.

Constitutive modelling of the mechanical response of a polycaprolactone based polyurethane elastomer: Finite element analysis and experimental validation through a bulge test

2020 ◽  
pp. 030932472095833
Author(s):  
Nahuel Rull ◽  
Asanka Basnayake ◽  
Michael Heitzmann ◽  
Patricia M. Frontini
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Mechanical Response ◽  
Strain Curve ◽  
Image Correlation ◽  
Bulge Test ◽  
Polyurethane Elastomer ◽  
Stress Strain ◽  
Element Analysis ◽  
Nonlinear Stress

The mechanical behaviour of a high performance polycaprolactone based polyurethane elastomer (PCL) up to large strain levels, cyclic loading and equibiaxial stress has been assessed. The PCL can be categorised as a rubber-like material, thus, showing nonlinear stress-strain behaviour. The materials elastic network is based on a high molecular weight PCL polyol which gives the material its elastomeric behaviour similar to polyurethanes. In this work, mechanical testing capturing the major features of the stress-strain curve under different loading conditions is performed. Both, uni-axial loading-unloading curves and bulge test are thoroughly studied through the addition of digital image correlation (DIC) to measure the strain field. Results show the presence of hysteresis and loading configuration dependence. Then, two well-known hyperelastic constitutive models, the Arruda-Boyce eight-chain and Bergström-Boyce, were fitted to the uni-axial monotonic and cyclic test data and compared to the bulge test experimental results through finite element analysis (FEA) in Abaqus.

Based on Experiment of Constitutive Model of Load-Bearing Insulation Masonry

2012 ◽  
Vol 204-208 ◽  
pp. 1089-1093
Author(s):  
Xi Jun Liu ◽  
Lin Xiang Liu ◽  
Yu Mei Wang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Constitutive Model ◽  
Thermal Insulation ◽  
Maximum Stress ◽  
Stress And Strain ◽  
Stress Strain ◽  
Element Analysis ◽  
Composite Wall ◽  
Insulation Wall

In order to obtained the constitutive equations of thermal insulation masonry, the four masonry with different angles has pressed. Study on thermal insulation of masonry compressive mechanical parameters of constitutive equation and two-stage by compression stress-strain curves obtained in the servo press machine tests and data processing. The Basic mechanics parameters can be provided for finite element analysis of thermal insulation composite wall. The experiments showed that the constitutive model is discretization and the maximum stress and strain by press machine testing is different from brick masonry. The constitutive model is close with curve by press machine testing. The performance of mechanics in thermal insulation wall can be application by the stress-strain curves of thermal insulation of masonry. The stress-strain curves based experiments can be used finite element analysis of thermal insulation wall.

Finite Element Analysis for Prediction of Permanent Growth of Rotating Disc of Aero Engine During Over-Speed and Burst-Speed Conditions and Validation of Results Through Experiment

2013 ◽  
Author(s):  
M. Rudra Goud ◽  
C. Manjunatha ◽  
M. Venkateshwarlu ◽  
B. V. A. Patnaik
Keyword(s):  
Finite Element ◽  
Plastic Material ◽  
Strain Curve ◽  
Element Model ◽  
Rotating Disc ◽  
Stress Strain ◽  
Element Analysis ◽  
Non Linear ◽  
Strain Relationship ◽  
Elastic Plastic Material

The service life of critical aerospace components is governed by the modes of degradation and failure such as: yielding, fatigue, fracture, creep, corrosion, wear, etc. A single disc is used for over-speed and burst-speed tests to know the growths (plastic deformation). In this paper, a cyclic symmetry sector of disc model with non linear elastic-plastic material is considered. A non-linear finite element method is utilized to determine the stress and strain state of the disc under over-speed and burst-speed conditions using material stress strain curves. Permanent growths and strains obtained from the over-speed analysis are incorporated in the burst-speed Finite element Model. The original stress strain curve used in over-speed analysis is modified with plastic strain and used in burst-speed analysis of same disc. Elastic strains obtained from the over-speed and burst-speed analysis are utilized in stress strain relationship equations to calculate the permanent growths at critical locations of disc. Growths predicted from Analysis are comparable with the experimental results of disc where a maximum variation of 11% at bore and rim of disc is observed.

scholarly journals Proposed Constitutive Law of Uniaxial Compression for Concrete under Deterioration Effects

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2048 ◽  
Author(s):  
Yiwei Gao ◽  
Xuhua Ren ◽  
Jixun Zhang ◽  
Lingwei Zhong ◽  
Shuyang Yu ◽  
...  
Keyword(s):  
Uniaxial Compression ◽  
Failure Process ◽  
Strain Curve ◽  
Ductile Deformation ◽  
Deformation Capacity ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
New Model ◽  
Freeze Thaw ◽  
Prediction Curve

In order to study the ductile deformation characteristics and failure process of plain concrete under uniaxial compression, this paper proposes a new constitutive model. The new model was used to fit and analyze the constitutive curve of concrete under uniaxial compressive under various degradation forms and was compared with the traditional constitutive models. Finally, the new model was used to quantitatively analyze and predict the stress–strain curve of concrete in different degradation periods of a set of freeze–thaw measured data. The results show that, compared with the traditional constitutive model, the new model is simple in form and has few parameters, and the numerical value of the parameter can reflect the ductile deformation capacity of concrete. The fitting curve of the new model has the highest fitting degree with the measured stress–strain curve of concrete, and the goodness of fit (R2) is also the largest. The new model is suitable for fitting the stress–strain curve of concrete under uniaxial compression under various deteriorating forms, and the degree of fit between the constitutive prediction curve and the measured curve is high. It can be seen from the fitting results of the new model parameters that the ductile deformation capacity of concrete decreases first and then increases slightly, which is inconsistent with the law of gradual deterioration of strength. There is a minimum moment of ductility deformation capacity of concrete (MDC). The MDC of O-C40 concrete is about 114 freeze–thaw cycles, and the MDC of O-C50 concrete is about 116 freeze–thaw cycles; the degree of fit between the constitutive prediction curve and the measured curve is high. We hope that the improvement mentioned offers valid reference to the study of ductile deformation characteristics and failure process of compressed concrete under different deterioration forms.

Sign in / Sign up

Export Citation Format

Share Document