Strain-Life Behavior in 60/40 Solder

1989 ◽  
Vol 111 (2) ◽  
pp. 75-82 ◽  
Author(s):  
H. D. Solomon
Keyword(s):  
Fatigue Life ◽  
Plastic Strain ◽  
Simple Shear ◽  
Curve Fitting ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Cycle Fatigue ◽  
Load Drop ◽  
Fitting Procedure ◽  
Life Behavior

This paper describes low cycle fatigue test run at −50°C, 35°C, 125°C, and 150°C on thin 60 Sn/40 Pb solder joints, tested in simple shear. The low cycle fatigue behavior was found to be a function of the criteria used to define the fatigue life. Different drops in the hysteresis load, measured when a constant plastic strain is being applied, was used to define failure. Not only was the magnitude of the fatigue life a function of the load drop definition for failure, it was also found that the Coffin-Manson low cycle fatigue exponent was a function of this definition. The choice of dependent variable for the curve fitting procedure used to calculate the Coffin-Manson exponent is also considered.

Low Cycle Fatigue of Sn96 Solder With Reference to Eutectic Solder and a High Pb Solder

1991 ◽  
Vol 113 (2) ◽  
pp. 102-108 ◽  
Author(s):  
H. D. Solomon
Keyword(s):  
Fatigue Life ◽  
Melting Point ◽  
Plastic Strain ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Cycle Fatigue ◽  
Eutectic Solder ◽  
Soldering Temperature ◽  
Higher Temperature ◽  
Strain Cycling

This paper describes the 35°C and 150°C low cycle fatigue behavior of Sn96 solder (96.5 Sn/3.5 AG), the tin silver eutectic. There is a considerable amount of anecdotal information which says that this solder is superior to eutectic solder in its fatigue resistance. This study generally supports this assertion, but not for all plastic strain ranges. This solder has an excellent balance of strength, ductility and fatigue life under strain cycling. Furthermore, it is also shown that this solder is superior to a high Pb solder (92.5 Pb/2.5 Ag/5.0 Sn). The only drawback of the tin silver eutectic is that it has a higher melting point than the melting point for the Sn/Pb eutectic (221°C versus 183°C), and this requires a higher soldering temperature. This higher temperature necessitates some process alterations in order to use this solder.

Low Cycle Fatigue Behavior of VVER-440 Reactor Pressure Vessel Steels at Isothermal Condition

2015 ◽  
Vol 812 ◽  
pp. 47-52 ◽  
Author(s):  
Balazs Fekete ◽  
Peter Bereczki ◽  
Peter Trampus
Keyword(s):  
Fatigue Life ◽  
Plastic Strain ◽  
Pressure Vessel ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Isothermal Condition ◽  
Reactor Pressure Vessel ◽  
Cycle Fatigue ◽  
Pressure Vessel Steels ◽  
Reactor Pressure

The fatigue life of the structural materials 15H2MFA and 08H18N10T of VVER-440 reactor pressure vessel under completely reserved total strain controlled tests were investigated. The measurements were carried out with isothermal condition at 260°C on GLEEBLE 3800 servo-hydraulic thermal mechanical simulator. The isothermal low cycle fatigue results were evaluated with the plastic strain based Coffin-Manson law, and plastic strain energy based model as well. It was shown that both methods are able to predict the fatigue life of reactor pressure vessel steels accurately.

LOW CYCLE FATIGUE BEHAVIOR AND LIFE PREDICTION OF A CAST COBALT-BASED SUPERALLOY

2012 ◽  
Vol 06 ◽  
pp. 251-256
Author(s):  
HO-YOUNG YANG ◽  
JAE-HOON KIM ◽  
KEUN-BONG YOO
Keyword(s):  
Fatigue Life ◽  
Strain Energy ◽  
Life Prediction ◽  
Prediction Models ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Total Strain ◽  
Cycle Fatigue ◽  
Total Strain Range ◽  
Different Temperatures

Co -base superalloys have been applied in the stationary components of gas turbine owing to their excellent high temperature properties. Low cycle fatigue data on ECY-768 reported in a companion paper were used to evaluate fatigue life prediction models. In this study, low cycle fatigue tests are performed as the variables of total strain range and temperatures. The relations between plastic and total strain energy densities and number of cycles to failure are examined in order to predict the low cycle fatigue life of Cobalt-based super alloy at different temperatures. The fatigue lives is evaluated using predicted by Coffin-Manson method and strain energy methods is compared with the measured fatigue lives at different temperatures. The microstructure observing was performed for how affect able to low-cycle fatigue life by increasing the temperature.

Low-Cycle Fatigue Life of Continuously Cyclic-Hardening Material

2020 ◽  
Author(s):  
Zhong Zhang ◽  
Xijia Wu
Keyword(s):  
Fatigue Life ◽  
Plastic Strain ◽  
Root Mean Square ◽  
Low Cycle Fatigue ◽  
Cyclic Hardening ◽  
Mean Square ◽  
Cycle Fatigue ◽  
Fatigue Crack Nucleation ◽  
Hardening Material ◽  
Plastic Strain Range

Abstract A general fatigue life equation is derived by modifying the Tanaka-Mura-Wu dislocation pile-up model for variable strain-amplitude fatigue processes, where the fatigue crack nucleation life is expressed in terms of the root mean square of plastic strain range. Low-cycle fatigue tests were conducted on an austenitic stainless steel. at 400°C and 600°C, the material exhibits continuously cyclic-hardening behaviour. The root mean square of plastic strain ranges is evaluated from the experimental data for each test condition at strain rates ranging from 0.0002/s to 0.02/s. The variable-amplitude Tanaka-Mura-Wu model is found to be in good agreement with the LCF data, which effectively proves Miner’s rule on the stored plastic strain energy basis.

Low-Cycle Fatigue Life of Continuously Cyclic-Hardening Material

2021 ◽  
Author(s):  
Zhong Zhang ◽  
Xijia Wu
Keyword(s):  
Fatigue Life ◽  
Plastic Strain ◽  
Root Mean Square ◽  
Low Cycle Fatigue ◽  
Cyclic Hardening ◽  
Mean Square ◽  
Cycle Fatigue ◽  
Fatigue Crack Nucleation ◽  
Hardening Material ◽  
Plastic Strain Range

Abstract A general fatigue life equation is derived by modifying the Tanaka-Mura-Wu dislocation pile-up model for variable strain-amplitude fatigue processes, where the fatigue crack nucleation life is expressed in terms of the root mean square of plastic strain range. Low-cycle fatigue tests were conducted on an austenitic stainless steel. At 400 ? and 600 ?, the material exhibits continuously cyclic-hardening behaviour. The root mean square of plastic strain ranges is evaluated from the experimental data for each test condition at strain rates ranging from 0.0002/s to 0.02/s. The variable-amplitude Tanaka-Mura-Wu model is found to be in good agreement with the LCF data, which effectively proves Miner's rule on the stored plastic strain energy basis.

Transition From Low Cycle to High Cycle in Uniaxial Fatigue

2013 ◽  
Author(s):  
Mohamed E. M. El-Sayed
Keyword(s):  
Fatigue Life ◽  
High Cycle Fatigue ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Uniaxial Stress ◽  
Life Assessment ◽  
Elastic Behavior ◽  
Cycle Fatigue ◽  
Fatigue Life Assessment ◽  
Component Development

Fatigue is the most critical failure mode of many mechanical component. Therefore, fatigue life assessment under fluctuating loads during component development is essential. The most important requirement for any fatigue life assessment is knowledge of the relationships between stresses, strains, and fatigue life for the material under consideration. These relationships, for any given material, are mostly unique and dependent on its fatigue behavior. Since the work of Wöhler in the 1850’s, the uniaxial stress versus cycles to fatigue failure, which is known as the S-N curve, is typically utilized for high-cycle fatigue. In general, high cycle fatigue implies linear elastic behavior and causes failure after more than 104 or 105 cycles. However. the transition from low cycle fatigue to high cycle fatigue, which is unique for each material based on its properties, has not been well examined. In this paper, this transition is studied and a material dependent number of cycles for the transition is derived based on the material properties. Some implications of this derivation, on assessing and approximating the crack initiation fatigue life, are also discussed.

Modeling, Simulation, and Experimentation of Fatigue Behavior in Amorphous Solids

2018 ◽  
Vol 774 ◽  
pp. 210-216 ◽  
Author(s):  
Thierry Barriere ◽  
Gang Cheng ◽  
Sami Holopainen
Keyword(s):  
Fatigue Life ◽  
Fatigue Damage ◽  
Stress Reduction ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Amorphous Solids ◽  
Cycle Fatigue ◽  
Unified Approach ◽  
Structural Element ◽  
Modeling Simulation

Amorphous solids, such as certain polymers, alloys, and polymer-based composites,are increasingly used materials in engineering components and thus, their fatigue behavioris of utmost importance. The article presents a unified approach suitable for modeling bothisothermal high cycle and low cycle fatigue behavior. The emphasis is placed on the ductilefatigue in which fatigue damage represents the material degeneration during the creation ofmicro-cracks governing majority of the total fatigue life (up to 95%). The model’s capability fortechnologically important polycarbonate (PC) polymer is addressed. The results, in accordancewith experimental observations, favor ductile fatigue behavior, i.e. damage fields remain smallfor most of the fatigue life and do not cause the macroscopic stress reduction. Due to thisproperty, fatigue life of an entire structural element can be evaluated by exploiting singlelocations at which the fatigue damage decisively emerges.

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