Effects of temperature, strain rate, and cyclic loading on mechanical behavior of silane‐modified polyurethane sealant

2020 ◽  
pp. 50195
Author(s):  
Jun Zhang ◽  
Hao zhong Shen ◽  
Hai yu Li ◽  
Liu feng Gu
Keyword(s):  
Cyclic Loading ◽  
Strain Rate ◽  
Mechanical Behavior ◽  
Effects Of Temperature ◽  
Temperature Strain

Effects of Temperature, Strain Rate and Grain Size on Superplastic Behavior of Magnesium

2012 ◽  
Vol 488-489 ◽  
pp. 27-34 ◽  
Author(s):  
Muhammad Waseem Soomro ◽  
Thomas Rainer Neitzert
Keyword(s):  
Grain Size ◽  
Strain Rate ◽  
Magnesium Alloys ◽  
Room Temperature ◽  
Superplastic Forming ◽  
Experimental Results ◽  
Superplastic Behavior ◽  
Influence Of Temperature ◽  
Effects Of Temperature ◽  
Temperature Strain

The influence of temperature, grain size and strain rate on superplasticity of magnesium is investigated. Different approaches are compared along with their experimental results to show the variation in the amount of superplasticity by varying above mentioned parameters. At room temperature magnesium alloys usually have poor formability but recent studies of some alloys such as ZE10, AZ31, AZ61 AZ60, AZ80 and AZ91 are pointing that by varying the temperature along with grain size and strain rate improved formability is possible or even superplastic forming of these alloys can be achieved to meet the demands of automotive, aircraft and other weight conscious industries.

The Effects of Temperature, Strain Rate, and Aging on the Poisson’s Ratio of SAC Lead Free Solders

2018 ◽  
Author(s):  
K. M. Rafidh Hassan ◽  
Mohammad S. Alam ◽  
Munshi Basit ◽  
Jeffrey C. Suhling ◽  
Pradeep Lall
Keyword(s):  
Finite Element ◽  
Strain Rate ◽  
Poisson’S Ratio ◽  
Poisson's Ratio ◽  
Lead Free ◽  
Uniaxial Tensile ◽  
Automatic Data ◽  
Effects Of Temperature ◽  
Lead Free Solders ◽  
Temperature Strain

In this study, we have conducted a combined numerical and experimental study on the Poisson’s ratio of SAC lead free solders. The Poisson’s ratio (PR) is one of the basic mechanical properties used in many material constitutive models. Although often not measured, it is important property in many finite element method (FEM) calculations. The value of the Poisson’s ratio of SAC lead free solders is relatively unexplored compared to other material properties, and for FEA simulations it is typically assumed to be v = 0.3. In the current work, we have shown the effects of the chosen value of the solder joint Poisson’s ratio on the finite element results for BGA components subjected to thermal cycling. In the finite element models, the reliability predictions were based on the Morrow-Darveaux energy-based fatigue model. Several sizes (5, 10, 15 mm) of PBGA components with SAC305 solder joints with 0.4 and 0.8 mm spacing were modeled. The packages were subjected to a time dependent cyclic temperature distribution from −40 to 125 °C. The package assemblies were assumed to be in a stress-free state at 25 °C (room temperature), with no residual stresses induced in the manufacturing process. The simulation results have demonstrated that for specified range of Poisson’s ratio values of 0.15 < v < 0.40, the solder Plastic Work varied over 20% and the Predicted Reliability Varied over 50%. To determine the actual Poisson’s ratio experimentally, uniaxial tensile stress-strain tests were carried out on SAC305 (96.5Sn3.0Ag0.5Cu) specimens using a micro tension/torsion testing machine with two strain rates (0.0001, and 0.00001 (sec−1)), four testing temperatures (T = 25, 50, 75, 100 °C), and several durations of prior aging at T = 125 °C. Deformations and strains in axial and transverse directions were measured using strain gages with automatic data acquisition from LabVIEW software. The recorded transverse strain vs. axial strain data were then fit with a linear regression analysis to determine the Poisson’s ratio values. A test matrix of experiments was developed to study the effects of temperature, strain rate, alloy composition, and solidification cooling profile on the value of solder Poisson’s ratio. The Poisson’s ratio was found to increase with increasing temperature, and decrease with increasing strain rate. Using a slower solidification cooling profile led to an increase in the solder Poisson’s ratio value. Finally, the microstructural coarsening that occurs during isothermal aging lead to an increase in the Poisson’s ratio.

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