scholarly journals Dominance distributions for fatigue performance of materials and its application in material selection

2020 ◽  
Author(s):  
Xin Bai ◽  
Peng Zhang ◽  
Enna Yang ◽  
Qiqiang Duan ◽  
Hao Bo ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Fatigue Life ◽  
Probability Distribution ◽  
Reliability Index ◽  
Material Selection ◽  
Fatigue Property ◽  
Fatigue Performance ◽  
New Method ◽  
Variable Amplitude ◽  
Casting Alloys

A new method for the comparison of fatigue performance among different materials is proposed by using Monte-Carlo technology. The uncertainty of material’s fatigue property and the diversity of service loads are respectively described as a reliability index and a probability distribution. Using fatigue life as the standard measure of fatigue performance, two kinds of diagrams are developed as the dominance distributions for fatigue performance of materials. After the implication in the material selection from two casting alloys, the results show that the new method can evaluate the fatigue performance among different materials no matter withsanding constant or variable amplitude loading, which is very easy to guide the judgment whether the material has better fatigue performance or not.

Low-Cycle Fatigue Performance of Buckling Restrained Braces and Assessment of Cumulative Damage under Severe Earthquakes

2018 ◽  
Vol 763 ◽  
pp. 867-874
Author(s):  
Yu Shu Liu ◽  
Ke Peng Chen ◽  
Guo Qiang Li ◽  
Fei Fei Sun
Keyword(s):  
Fatigue Life ◽  
Energy Dissipation ◽  
Structural Reliability ◽  
Low Cycle Fatigue ◽  
Engineering Application ◽  
Fatigue Performance ◽  
Cycle Fatigue ◽  
Variable Amplitude ◽  
Buckling Restrained Braces ◽  
Energy Dissipation Devices

Buckling Restrained Braces (BRBs) are effective energy dissipation devices. The key advantages of BRB are its comparable tensile and compressive behavior and stable energy dissipation capacity. In this paper, low-cycle fatigue performance of domestic BRBs is obtained based on collected experimental data under constant and variable amplitude loadings. The results show that the relationship between fatigue life and strain amplitude satisfies the Mason-Coffin equation. By adopting theory of structural reliability, this paper presents several allowable fatigue life curves with different confidential levels. Besides, Palmgren-Miner method was used for calculating BRB cumulative damages. An allowable damage factor with 95% confidential level is put forward for assessing damage under variable amplitude fatigue. In addition, this paper presents an empirical criterion with rain flow algorithm, which may be used to predict the fracture of BRBs under severe earthquakes and provide theory and method for their engineering application. Finally, the conclusions of the paper were vilified through precise yet conservative prediction of the fatigue failure of BRB.

Fatigue Performance of Concrete with Pre-Cracks in Tension-Compression Cycles

2014 ◽  
Vol 584-586 ◽  
pp. 1054-1061
Author(s):  
Jian Shen ◽  
Xiao Yun Liu ◽  
Lang Wu
Keyword(s):  
Fatigue Life ◽  
Fatigue Strength ◽  
Cyclic Loading ◽  
Fatigue Test ◽  
Stress Ratio ◽  
Fatigue Property ◽  
Fatigue Performance ◽  
Cycle Fatigue ◽  
Fatigue Load ◽  
Compression Cycle

A tension-compression cycle fatigue test was performed in order to study the fatigue property of C50 concrete with pre-cracks in cyclic loading. The stress ratio was-1 and the amplitude was 0.2 MPa ~1.30 MPa. The results show that the modified coefficient of fatigue strength is 0.198~0.265 and the infinite life fatigue strength is below 0.45MPa. While the log value of fatigue life is approximately linear with the amplitude of fatigue load stress, the discreteness of fatigue life, the particularity of concrete, has little to do with the amplitude. The S-N, P-N fatigue life curves and the constant fatigue life diagram of pre-crack concrete are obtained.

Study on Probability Distribution of Ship-Bridge Collision Force Formula

2013 ◽  
Vol 423-426 ◽  
pp. 1150-1154
Author(s):  
Jun Hu Shao ◽  
Shuai Song
Keyword(s):  
Monte Carlo ◽  
Probability Distribution ◽  
Reliability Index ◽  
Extreme Value Distribution ◽  
Generalized Extreme Value Distribution ◽  
Distribution Characteristics ◽  
Distribution Fitting ◽  
Ship Collision ◽  
Collision Force ◽  
Index Calculation

The probability distribution with different ship-bridge collision formulas are studied using Monte-Carlo method. It used the distribution fitting tool with the sampling results, and got the forms and parameter of probability distribution of different ship-bridge collision force formulas. The results indicate that the logarithmic normal distribution and generalized extreme value distribution can well reflect the probability distribution characteristics of ship-bridge collision formula. The probability distribution characteristics proposed can be directly used in the reliability index calculation of bridge under the ship collision.

Fatigue Life Reliability Analysis of Submarine Cone-Cylinder Shell

2012 ◽  
Vol 479-481 ◽  
pp. 2001-2004
Author(s):  
Zhi Yong Zhang ◽  
Tian Shu Song ◽  
Yang He
Keyword(s):  
Monte Carlo ◽  
Fatigue Life ◽  
Monte Carlo Method ◽  
Fracture Mechanics ◽  
Reliability Analysis ◽  
The Other ◽  
New Method ◽  
Probabilistic Fracture Mechanics ◽  
Two Factors

A new method is presented in the paper. The fatigue life reliability of submarine cone-cylinder shell is investigated, based on the combination between the methods of conventional Monte Carlo and classical probabilistic fracture mechanics. Firstly, Monte Carlo method is employed to obtain the reliability of given initial fatigue life. Secondly, the two induced factors M1 and M2 in the paper are estimated according to the initial fatigue life and the reliability. Thirdly, based on the two factors, the other fatigue life reliability is obtained by using classical probabilistic fracture mechanics method. Finally, numerical cases show that the proposed method is more efficient without accuracy loss for fatigue life reliability compared with Monte Carlo method. This method can also be applied to predict the fatigue life reliability of analogue structures.

scholarly journals Study on Structural Reliability of Prestressed Reinforced Concrete Beam Bridges Based on Full Probability Analysis

2021 ◽  
Vol 1210 (1) ◽  
pp. 012003
Author(s):  
Yubao Liu ◽  
Hanxiong Liu ◽  
Shouyi Sun
Keyword(s):  
Finite Element ◽  
Monte Carlo ◽  
Monte Carlo Method ◽  
Probability Distribution ◽  
Reliability Index ◽  
Limit State ◽  
State Equation ◽  
Distribution Model ◽  
State Equations ◽  
The Monte Carlo Method

Abstract A three dimensional(3D) finite element model is established for a prestressed concrete girder bridge, list the limit state equation and variable probability distribution model, obtain the failure probability and reliability index of the limit state equation based on the Monte-Carlo method, investigate the reliability index’s sensitivity to random variables for limit state equations of bridge bearing capacity. The specific method of the research on the structure reliability index calculation is to select a suitable way that can fit the research’s object among the center point method, the checking-point method, the Monte-Carlo method, the importance sampling method, and so on. Authors use finite element software ANSYS to build model and perform 3D force analysis. According to the results, authors can determine the bridges’ failure modes under the state of 3D stress. Then, authors can list the possible limit state equations related to Stiffness, strength, function, durability, and some character else. After determining the bridge’s structural limit state equation and the probability distribution model of the variables, determine the distribution function of each impact factor and its characteristic parameters through the site survey data and other related data surveys. Then, use the Monte-Carlo method for the calculation of bridge reliability index, obtain the failure probability and reliability index of each limit state equation, analyze the sensitivity of each variable to the reliability index under the ultimate state of the bridge’s bearing capacity. At last, authors give construction quality control plans and suggestions according to the data above.

Improve the Fatigue Performance of Welded Joints with Undercuts by TIG Dressing Treatment

2012 ◽  
Vol 472-475 ◽  
pp. 1300-1304 ◽  
Author(s):  
Liang Chen Wu ◽  
Dong Po Wang
Keyword(s):  
Fatigue Life ◽  
Fatigue Strength ◽  
Adverse Effects ◽  
Dynamic Loading ◽  
Weld Joint ◽  
Welded Joints ◽  
Fatigue Cracks ◽  
Fatigue Property ◽  
Fatigue Performance ◽  
Weld Toe

Undercuts often exists in the surface at weld toe. Undercuts affects the capability of weld subjected to dynamic loading greatly and fatigue cracks usually initiate from these zones with undercuts. Combining with low-alloy middle strength steel 16Mn，study of increasing the fatigue strength and the fatigue life was carried out. Compared with specimen without defects, the fatigue strength of specimen with undercuts has been increased by 10~20%. Study also shows that comparing with as-welded specimen with defects, with TIG dressing treatment, fatigue strength of cruciform weld joint of steel 16Mn has been increased by 70%, fatigue life by 5~8 times. Compared with as-welded specimen without defects, fatigue strength has been increased by 34%, fatigue life by 3~4 times. Undercuts have no adverse effects on fatigue property of welded joints under TIG dressing.

Sign in / Sign up

Export Citation Format

Share Document