Fatigue Life Prediction of Heat-Aging Vulcanized Natural Rubber

2006 ◽  
Vol 321-323 ◽  
pp. 518-521 ◽  
Author(s):  
Chang Su Woo ◽  
Wan Doo Kim
Keyword(s):  
Fatigue Life ◽  
Natural Rubber ◽  
Life Prediction ◽  
Prediction Equation ◽  
Damage Parameter ◽  
Fatigue Life Prediction ◽  
Aging Effects ◽  
Element Analysis ◽  
Fatigue Damage Parameter ◽  
Lagrange Strain

Heat-aging effects on the material properties and fatigue life prediction of natural rubber were experimentally investigated. The rubber specimens were heat-aged in an oven at the temperature ranging from 50oC to 100oC for a period ranging from 1 day to 90days. Fatigue life prediction methodology of vulcanized natural rubber was proposed by incorporating the finite element analysis and fatigue damage parameter determined from fatigue test. Fatigue life prediction equation effectively represented by a single function using the Green-Lagrange strain. Predicted lives are in a good agreement with the experimental lives within a factor of two

Fatigue Behaviour of Lead-Free Solder Interconnections in Life Prediction of Trilayer Structures Subjected to Thermal Cycling

2015 ◽  
Author(s):  
Alireza Shirazi ◽  
Hua Lu ◽  
Ahmad Varvani-Farahani
Keyword(s):  
Fatigue Life ◽  
Fatigue Damage ◽  
Life Prediction ◽  
Damage Parameter ◽  
Fatigue Life Prediction ◽  
Lead Free Solder ◽  
Critical Plane ◽  
Trilayer Structure ◽  
Fatigue Damage Parameter ◽  
Free Solder

Trilayer structures such as flip chip plastic ball grid array (FC-PBGA) packages are bodies made of a large variety of dissimilar materials. Due to the coefficients of thermal expansion (CTE) mismatches between and temperature gradients within the layers, thermally induced interaction becomes a typical type of the loads for the joint layer made of lead-free solder joint interconnections. Thermal stresses and strains at the interfaces of solder joints and neighboring adhesive layers are the cause for solder joint fatigue failures, which account for the most common package failures. The current study puts forward a fatigue life prediction method for a trilayer structure using the critical plane-energy fatigue damage parameter in combination with the modified Coffin-Manson life model. The proposed method of calculated fatigue damage parameter for the samples of study, along with their experimental life (Nf50%) under two different thermal conditions is presented. The values of life in (0–100°C) condition and (25–125°C) with the same temperature ramp rate and dwell conditions are found to differ by a factor of 1.3 where the structures tested under (0–100°C) condition show lower lives. The present study further correlated the fatigue damage parameters with the Coffin-Manson type equation to calculate/predict the fatigue life of structures under (25–125°C) condition. The results of the Nf50 fatigue life prediction versus the experimental cycles show that the predicted lives of samples with SAC305 solder joints fall apart with a factor ranging from (1.24)∼(−1.45). The advantage of the proposed method in comparison with the existing methods in life prediction of the trilayer structure with solder alloy is that there are no empirical parameters involved in energy-critical plane damage parameter in life prediction of the trilayer structure. Parameters within the proposed approach purely involves mechanical and fatigue properties of the midlayer alloy.

A Study on the Fatigue Life Prediction and Evaluation of the Natural Rubber Components for Automobile Vehicles

2006 ◽  
Vol 326-328 ◽  
pp. 589-592
Author(s):  
Chang Su Woo ◽  
Wan Doo Kim ◽  
Jae Do Kwon
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Fatigue Life ◽  
Natural Rubber ◽  
Fatigue Damage ◽  
Damage Parameter ◽  
Fatigue Tests ◽  
Element Analysis ◽  
Engine Mount ◽  
Lagrange Strain

The fatigue analysis and lifetime evaluation are very important in design procedure to assure the safety and reliability of the rubber components. The interest of the fatigue life of rubber components such as the engine mount is increasing according to the extension of warranty period of the automotive components. In this study, the fatigue lifetime prediction methodology of the vulcanized natural rubber was proposed by incorporating the finite element analysis and fatigue damage parameter determined from fatigue tests. Finite element analysis of 3D dumbbell specimen of natural rubber was performed based on a hyper-elastic material model determined from the tension, compression and shear tests. The Green-Lagrange strain at the critical location determined from the finite element analysis was used for evaluating the fatigue damage parameter of the natural rubber. Fatigue tests were performed using the 3D dumbbell specimens with different levels of maximum strain and various load. The basic mechanical properties test and the fatigue test of rubber specimens under the normal and elevated temperature were conducted. Fatigue life curves can be effectively represented by a following single function using the maximum Green-Lagrange strain. Fatigue lives of the natural rubber are predicted by using the fatigue damage parameters at the critical location. Predicted fatigue lives of the engine mount agreed fairly with the experimental fatigue lives a factor of two.

Research on Fretting Fatigue Life of Interference Fit and its Influencing Factors

2012 ◽  
Vol 251 ◽  
pp. 293-300 ◽  
Author(s):  
Chang Wu Huang ◽  
Guang Xue Yang ◽  
Nian Jun Fu ◽  
Ji Long Xie
Keyword(s):  
Fatigue Life ◽  
Life Prediction ◽  
Prediction Models ◽  
Fretting Fatigue ◽  
Damage Parameter ◽  
Fatigue Life Prediction ◽  
Element Analysis ◽  
Interference Fit ◽  
Bending Loads ◽  
Fretting Damage

Interference-Fit Components, Especially under Rotating Bending Loads, Usually Suffer Fretting Fatigue, which Tremendously Reduces Service Lives of the Components. by Taking Specimens with Different Interference-Fit Parameters for Fatigue Test, their Fretting Fatigue Lives Could Be Obtained. and through Using Finite Element Analysis (FEA) Software ABAQUS, the Ruiz Fretting Damage Parameter K(x) for each Tested Fatigue Specimen Were Achieved. then, According to the Test Data and the Results of Calculations, Two Fretting-Fatigue Life Prediction Models (model 1：N=c•K-α, and Model 2：N=λN0—m•Kn) )based on the Ruiz Fretting Damage Parameter Were Fitted, and their Ratλionalities and Validities Were Analyzed. at the same Time, the Influences of Interference-Fit Parameters -Interference Value (V), Casing outside Diameter (D), and Casing Length (L), Contact Pressure (p) and Friction Shear Stress (τ) on Fretting Fatigue Life Have Been Analyzed. the Results Showed that the Two Fitalic Textretting Fatigue Life Prediction Models Used in this Paper Were Valid, but, in Contrast, the Second One Was More Accurate and Rational; and that Fretting Fatigue Life (N) Decreased as V, D, L, P or τ Increasing.

scholarly journals Fatigue Life Prediction of Half-Shaft Using the Strain-Life Method

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Xipei Ma ◽  
Xintian Liu ◽  
Haijie Wang ◽  
Jiachi Tong ◽  
Xiaobing Yang
Keyword(s):  
Fatigue Life ◽  
Fatigue Damage ◽  
Life Prediction ◽  
Prediction Method ◽  
Local Stress ◽  
Damage Parameter ◽  
Fatigue Life Prediction ◽  
Maximum Shear Strain ◽  
Durability Analysis ◽  
Fatigue Damage Parameter

Fatigue life prediction is an important part of the reliability and durability analysis of automobile components. Based on Wang and Brown’s framework, multiaxial random fatigue damage was adopted to predict the fatigue life of half-shaft. The stress analysis of half-shaft was resolved analytically to determine the local stress tensor in the potential area of fracture. The maximum shear strain fatigue damage parameter and the normal stress fatigue damage parameter were evaluated to predict the fatigue life of half-shaft. The results show that the prediction method is reliable and meets the service life and safety requirements.

Review of Multiaxial Fatigue Life Prediction Technology under Complex Loading

2010 ◽  
Vol 118-120 ◽  
pp. 283-288 ◽  
Author(s):  
Lei Wang ◽  
Wu Zhen Li ◽  
Tian Zhong Sui
Keyword(s):  
Fatigue Life ◽  
Life Prediction ◽  
Prediction Models ◽  
Complex Loading ◽  
Damage Parameter ◽  
Multiaxial Fatigue ◽  
Fatigue Life Prediction ◽  
Theoretical Research ◽  
Practical Engineering ◽  
Fatigue Damage Parameter

The research on multiaxial fatigue life prediction methods is reviewed in the present paper from two aspects of experiment and theory. It is pointed out that the reasonable methods of the critical plane determining, multiaxial cycle counting and multiaxial fatigue damage parameter fixing are necessary if the fatigue life prediction models established under the multiaxial constant amplitude loading were applied to the life prediction of the complex multiaxial load. The shortcomings of existing researches are discussed. In the aspect of experiment, it is devoid of the multiaxial fatigue test that the loading components acted with different frequencies, and in the aspect of theory, the additional hardening effect of the multiaxial out-of-frequency loading is not considered. Both in the theoretical research and practical engineering applications, the problem of the out-of-frequency multiaxial loading is a pressing issue.

Fatigue Life Evaluation of Rubber Components for Automobile Vehicles

2006 ◽  
Vol 324-325 ◽  
pp. 181-184
Author(s):  
Chang Su Woo ◽  
Wan Doo Kim ◽  
Jae Do Kwon
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Fatigue Life ◽  
Natural Rubber ◽  
Fatigue Damage ◽  
Damage Parameter ◽  
Fatigue Tests ◽  
Element Analysis ◽  
Rubber Component ◽  
Lagrange Strain

The interest of the fatigue life for rubber components was increasing according to the extension of warranty period of the automotive components. In this study, the fatigue lifetime prediction methodology of the vulcanized natural rubber was proposed by incorporating the finite element analysis and fatigue damage parameter determined from fatigue tests. Finite element analysis of 3D dumbbell specimen and rubber component was performed based on a hyper-elastic material model determined from the mechanical tests. The Green-Lagrange strain at the critical location determined from the finite element analysis was used for evaluating the fatigue damage parameter of the natural rubber. Fatigue tests were performed using the 3D dumbbell specimens and rubber component with different levels of maximum strain and various load. Fatigue life curves can be effectively represented by a following single function using the maximum Green-Lagrange strain. Fatigue lives of the natural rubber are predicted by using the fatigue damage parameters at the critical location. Predicted fatigue lives of the rubber component for automobile vehicle agreed fairly with the experimental fatigue lives.

TTK Chitra tilting disc heart valve model TC2: An assessment of fatigue life and durability

2017 ◽  
Vol 231 (8) ◽  
pp. 758-765 ◽  
Author(s):  
NN Subhash ◽  
Adathala Rajeev ◽  
Sreedharan Sujesh ◽  
CV Muraleedharan
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Fatigue Life ◽  
Heart Valve ◽  
Life Prediction ◽  
Heart Valves ◽  
Failure Modes ◽  
Fatigue Life Prediction ◽  
Element Analysis ◽  
Valve Model

Average age group of heart valve replacement in India and most of the Third World countries is below 30 years. Hence, the valve for such patients need to be designed to have a service life of 50 years or more which corresponds to 2000 million cycles of operation. The purpose of this study was to assess the structural performance of the TTK Chitra tilting disc heart valve model TC2 and thereby address its durability. The TC2 model tilting disc heart valves were assessed to evaluate the risks connected with potential structural failure modes. To be more specific, the studies covered the finite element analysis–based fatigue life prediction and accelerated durability testing of the tilting disc heart valves for nine different valve sizes. First, finite element analysis–based fatigue life prediction showed that all nine valve sizes were in the infinite life region. Second, accelerated durability test showed that all nine valve sizes remained functional for 400 million cycles under experimental conditions. The study ensures the continued function of TC2 model tilting disc heart valves over duration in excess of 50 years. The results imply that the TC2 model valve designs are structurally safe, reliable and durable.

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