scholarly journals Assessment Model and Virtual Simulation for Fatigue Damage Evolution of Asphalt Mortar and Mixture

2018 ◽  
Vol 2018 ◽  
pp. 1-14
Author(s):  
Danhua Wang ◽  
Xunhao Ding ◽  
Linhao Gu ◽  
Tao Ma
Keyword(s):  
Fatigue Damage ◽  
Damage Evolution ◽  
Damage Model ◽  
Fatigue Tests ◽  
Assessment Model ◽  
Virtual Simulation ◽  
Coarse Aggregates ◽  
Four Point Bending ◽  
Formula Derivation ◽  
Asphalt Mortar

Focused on the fatigue performance of the asphalt mortar, this study proposed an assessment model for fatigue damage evolution based on the continuum mechanics. From the perspective of the material scale rather than the macrostructure, the proposed damage model was set by concentrating on the stress-strain state of a tiny point which could characterize the material performance accurately. By the mechanical formula derivation and based on the four-point bending fatigue tests, the damage evolution law was determined and then the proposed model was verified. Based on the finite element method (FEM), a commercial software named ABAQUS was utilized to develop the random mixtures consisting of coarse aggregates, mortar, and voids. Eventually, combined with the damage model and virtual simulation of bending tests, the factors influencing the fatigue resistance of the whole asphalt mixtures were analyzed further.

scholarly journals A Research on Fatigue Damage Constitutive Equation of Asphalt Mixture

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Yazhen Sun ◽  
Chenze Fang ◽  
Dong Fan ◽  
Jinchang Wang ◽  
Xuezhong Yuan
Keyword(s):  
Fatigue Damage ◽  
Damage Evolution ◽  
Damage Accumulation ◽  
Loading Rate ◽  
Damage Model ◽  
Asphalt Mixture ◽  
Fatigue Tests ◽  
Bending Fatigue ◽  
Three Point Bending ◽  
Three Stages

The laboratory investigations of fatigue damage constitutive equation of asphalt mixture were carried out by three-point bending fatigue tests. The three-point bending fatigue tests were performed at three levels of stress-strength ratio (SSR), temperature, and loading rate. The coupled multifactor (stress-strength ratio, temperature, and loading rate) fatigue life equation was established, which can well predict the fatigue life of the asphalt mixture. Both a damage model and a damage evolution equation have been established based on the E-N curve, which indicate that fatigue damage evolution is nonlinear and consists of three stages. The sensitivity analysis of damage model parameters indicates that each parameter has different effects on the three stages of damage evolution. Based on the researches above, the fatigue damage constitutive equations were finally built based on the σ-ε curves, which consist of two parts: the damage accumulation stage and the fatigue failure stage. The elasticity-power hardening model was used to describe the constitutive relation of damage accumulation stage. The elasticity-power hardening model and the Sidoroff damage model were used to describe the constitutive relation of damage failure stage. The constitutive equations can well characterize the fatigue damage performance of the asphalt mixtures under cyclic loading.

Analysis on High Cycle Fatigue Properties and Fatigue Damage Evolution of TC25 Titanium Alloy

2016 ◽  
Vol 697 ◽  
pp. 658-663
Author(s):  
Rong Guo Zhao ◽  
Ya Feng Liu ◽  
Yong Zhou Jiang ◽  
Xi Yan Luo ◽  
Qi Bang Li ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Fatigue Life ◽  
Strain Hardening ◽  
Fatigue Damage ◽  
Damage Evolution ◽  
High Cycle Fatigue ◽  
Damage Model ◽  
Fatigue Properties ◽  
Test Machine ◽  
Cycle Fatigue

The high cycle fatigue tests for smooth specimens of TC25 titanium alloy under different stress ratios are carried out on a MTS 809 Material Test Machine at a given maximum stress level of 917MPa at ambient temperature, the high cycle fatigue lifetimes for such alloy are measured, and the effects of stress amplitude and mean stress on high cycle fatigue life are analyzed. The initial resistance is measured at the two ends of smooth specimen of TC25 titanium alloy, every a certain cycles, the fatigue test is interrupted, and the current resistance values at various fatigue cycles are measured. The ratio of resistance change is adopted to characterize the fatigue damage evolution in TC25 titanium alloy, and a modified Chaboche damage model is applied to derive the fatigue damage evolution equation. The results show that the theoretical calculated values agree well with the test data, which indicates that the modified Chaboche damage model can precisely describe the accumulated damage in TC25 titanium alloy at high cycle fatigue under unaxial loading. Finally, the high cycle fatigue lifetimes for TC25 titanium alloy specimens at different strain hardening rates are tested at a given stress ratio of 0.1, the effect of strain hardening on fatigue life is investigated based on a microstructure analysis on TC25 titanium alloy, and an expression between fatigue life and strain hardening rate is derived

Damage Mechanics-Finite Element Full-Couple Method to Predict the Fatigue Life of Metallic Material

2014 ◽  
Vol 707 ◽  
pp. 390-396
Author(s):  
Xian Min Chen ◽  
Di Guan ◽  
Feng Ping Yang
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Fatigue Test ◽  
Fatigue Damage ◽  
Damage Evolution ◽  
Damage Mechanics ◽  
Fatigue Tests ◽  
Damage Initiation ◽  
Strain Threshold ◽  
Couple Method

A damage accumulation model is presented for fatigue life prediction of metallic structures. Based on the energy theory and material fatigue test data, the plastic strain threshold for damage initiation was modified for HCF and LCF respectively. The damage evolution parameters were determined according to the fatigue test results of standard specimens. A damage mechanics-finite element full-couple method was adopted to simulate the process of fatigue damage evolution, incorporating elastic modulus reduction due to fatigue damage. Comparisons are made with the fatigue tests of 2A12-T4 open-hole plates and good agreement was obtained.

A Probabilistic Fatigue Damage Model for Describing the Entire Set of Fatigue Test Data of the Same Material

2019 ◽  
Author(s):  
Xiaobin Le
Keyword(s):  
Fatigue Test ◽  
Fatigue Damage ◽  
Test Data ◽  
Stress Level ◽  
Damage Model ◽  
Fatigue Tests ◽  
Small Sample ◽  
Test Machine ◽  
Stress Levels ◽  
D Model

Abstract One typical widely-accepted approach for describing the fatigue test data is the P-S-N curve approach. However, the P-S-N curve approach has some issues such as: (1) If there are only a few fatigue test data at a fatigue test stress level, the P-S-N curve approach is not valid due to the small sample size; (2) When the total number of fatigue tests under different stress levels might be larger such as more than 30 even though the number of fatigue tests at the same stress level is small, the P-S-N curve cannot be used to analyze such set of fatigue data; (3) It is difficult to calculate the reliability of a component under a cyclic stress level when the probabilistic distribution function under this stress level is not available in the P-S-N curves. The author has proposed the K-D probabilistic fatigue damage model (K-D model) to overcome those issues. The 6061-T6 10-gauge sheet-type flat fatigue specimen was designed, manufactured, and tested on the Instron 8081 fatigue test machine to verify this K-D model. The fatigue tests were under five different cyclic axial loadings with a total of 195 tests. In this paper, the fatigue test data will be analyzed by the P-S-N curve approach and the K-D model. The systematic comparisons between the P-S-N curve approach and the K-D model have approved and verified that the K-D model can be used to analyze and to describe the fatigue test data under all different fatigue stress levels and can be used to calculate the reliability of a component under any type of cyclic fatigue loading.

A Probabilistic Fatigue Damage Model for Aluminum 6061-T6 10-Gauge Sheet-Type Material

2021 ◽  
Author(s):  
Xiaobin Le
Keyword(s):  
Fatigue Test ◽  
Fatigue Damage ◽  
Cyclic Load ◽  
Damage Model ◽  
Fatigue Tests ◽  
Load Level ◽  
Cyclic Loads ◽  
Test Machine ◽  
Axial Loads ◽  
Fatigue Specimen

Abstract The 6061-T6 10-gauge sheet-type flat fatigue specimen was designed, manufactured, and tested on an Instron 8081 fatigue test machine. The fatigue tests were performed under five different cyclic axial loads with 195 tests. This paper will display how to use these 195 test data under different cyclic axial loads to build a probabilistic fatigue damage model. The model is validated by the results obtained from the traditional P-S-N curve approach. One advantage of this probabilistic fatigue damage model is that it can calculate the reliability of a component under any type of cyclic loads at any cyclic load level.

A multi-scale corrosion fatigue damage model of high-strength bridge wires

2019 ◽  
Vol 29 (6) ◽  
pp. 887-901 ◽  
Author(s):  
Chen Fan ◽  
Zhaoxia Li ◽  
Ying Wang
Keyword(s):  
Fatigue Damage ◽  
Corrosion Fatigue ◽  
Damage Evolution ◽  
Damage Model ◽  
High Strength ◽  
Multi Scale ◽  
Faraday’S Law ◽  
Initiation And Propagation ◽  
Microcrack Propagation ◽  
Microcrack Initiation

Cables are the most sensitive components in cable-supported bridges, and the failure of cables is usually caused by the degradation of mechanical properties of internal wires. Based on Faraday's law and the rates of microcrack initiation and propagation, a multi-scale corrosion fatigue damage model was developed to describe the damage evolution in the stages of pit growth and microcrack propagation. The accuracy and effectiveness of this damage model were also verified through the experimental data of corrosive fatigue life of high-strength bridge wires. The result shows that this damage model can describe the multi-scale corrosion fatigue damage evolution process of high-strength bridge wires reasonably and effectively, which provides a new way to better understand the trans-scale damage evolution mechanism during the corrosion fatigue process of high-strength bridge wires.

scholarly journals Nonlinear Fatigue Damage Model of Asphalt Mixture Based on Dynamic Modulus and Residual Strength Decay

Materials ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2236 ◽  
Author(s):  
Hongfu Liu ◽  
Xinyu Yang ◽  
Chengdong Xia ◽  
Jianlong Zheng ◽  
Tuo Huang ◽  
...  
Keyword(s):  
Fatigue Damage ◽  
Residual Strength ◽  
Dynamic Modulus ◽  
Damage Model ◽  
Asphalt Mixture ◽  
Coupled Model ◽  
Tensile Tests ◽  
Fatigue Tests ◽  
Damage State ◽  
The Relationship

In order to describe the fatigue damage state of asphalt mixture more reasonably, direct tensile tests of the fatigue and the residual strength under stress levels of 1.00 MPa, 0.50 MPa and 0.25 MPa with five parallel tests were carried out. The trabecular specimens of AC-13C asphalt mixture (25 cm × 5 cm × 5 cm) were manufactured with Styrene-Butadiene-Styrene (SBS) modified asphalt, aggregate basalt and limestone mineral filler. The optimum asphalt-aggregate ratio was 5.2%. The dynamic modulus decay and the residual strength decay were termed as the damage variables to evaluate the fatigue damage process of asphalt mixtures, respectively. Based on the test results, the decay patterns of the dynamic modulus and the residual strength during fatigue tests under different stress states were revealed, and the model and the parameters of fatigue damage according to the corresponding decay patterns were obtained. Then, based on the assumption that the residual strength and dynamic modulus depend on the same damage state, the relationship between the two damage definitions was given, and the residual strength-dynamic modulus coupled model was established. The results showed that the residual strength-dynamic modulus coupled model could better describe the fatigue damage evolution law of asphalt mixture, and the parameter of this coupled model could be obtained by less residual strength tests. A modified formula for calculating the damage variables associated with residual strength and dynamic modulus was proposed based on the relationship between two kinds of damage variables.

Probabilistic Properties of Fatigue Damage and an Equivalent Damage Simplification Model for Multi-Level Load Spectra

2016 ◽  
Vol 08 (02) ◽  
pp. 1650017 ◽  
Author(s):  
X. R. Liu ◽  
Q. Sun
Keyword(s):  
Fatigue Damage ◽  
Damage Model ◽  
Fatigue Tests ◽  
Al Alloy ◽  
Test Results ◽  
Load Spectrum ◽  
Load Spectra ◽  
Multi Level ◽  
Load Sequence ◽  
Good Agreement

An equivalent fatigue damage simplification model for multi-level load spectrum is proposed. On the basis of the probabilistic fatigue damage model which takes load sequence effect into account and the constant amplitude fatigue tests, probabilistic properties of damage accumulated in one loading block are achieved quantitatively by statistical methods. The new simplification model can ensure that, for the original spectrum and simplified spectrum, the probabilistic properties of fatigue damage are almost the same. Fatigue tests for Al-alloy straight plates are performed to test the validity of the model. The test results are in good agreement with predicted results.

On the Use of Low and High Cycle Fatigue Damage Models

2013 ◽  
Vol 569-570 ◽  
pp. 1029-1035
Author(s):  
Magd Abdel Wahab ◽  
Irfan Hilmy ◽  
Reza Hojjati-Talemi
Keyword(s):  
Crack Initiation ◽  
Fatigue Damage ◽  
Damage Evolution ◽  
High Cycle Fatigue ◽  
Low Cycle Fatigue ◽  
Damage Model ◽  
Fretting Fatigue ◽  
Cycle Fatigue ◽  
Evolution Law ◽  
Number Of Cycles

In this paper, Continuum Damage Mechanics (CDM) theory is applied to low cycle and high cycle fatigue problems. Damage evolution laws are derived from thermodynamic principles and the fatigue number of cycles to crack initiation is expressed in terms of the range of applied stresses, triaxiality function and material constants termed as damage parameters. Low cycle fatigue damage evolution law is applied to adhesively bonded single lap joint. Damage parameters as function of stress are extracted from the fatigue tests and the damage model. High cycle fatigue damage model is applied to fretting fatigue test specimens and is integrated within a Finite Element Analysis (FEA) code in order to predict the number of cycles to crack initiation. Fretting fatigue problems involve two types of analyses; namely contact mechanics and damage/fracture mechanics. The high cycle fatigue damage evolution law takes into account the effect of different parameters such as contact geometry, axial stress, normal load and tangential load.

Sign in / Sign up

Export Citation Format

Share Document