scholarly journals Characterization of Strain Rate-Dependent Behavior of 63Sn-37Pb Solder Using Split Hopkinson Torsional Bars (SHTB)

2001 ◽  
Author(s):  
Shi-Wei Ricky Lee ◽  
Lan Hong Dai
Keyword(s):  
Solder Joint ◽  
Strain Rate ◽  
Shear Loading ◽  
Rate Dependent ◽  
Dependent Behavior ◽  
Split Hopkinson ◽  
Dynamic Shear Strength ◽  
Torsion Bar ◽  
Dependent Behaviour

Abstract The present study is aimed at the experimental characterization of strain-rate dependent behaviour of solder materials under impulsive shear loading. In order to achieve this objective, a unique testing technique, namely, split Hopkinson torsion bar (SHTB) is employed. The solder material under investigation is 63Sn-37Pb. The experimental results indicate that the shear behavior of the solder joint is very sensitive to the strain rate and the dynamic shear strength of the solder joint is much higher than the static one.

scholarly journals Strain Rate Dependent Behavior of Vinyl Nitrile Helmet Foam in Compression and Combined Compression and Shear

2020 ◽  
Vol 10 (22) ◽  
pp. 8286
Author(s):  
Nicolas Bailly ◽  
Yvan Petit ◽  
Jean-Michel Desrosier ◽  
Olivier Laperriere ◽  
Simon Langlois ◽  
...  
Keyword(s):  
Strain Rate ◽  
Shear Loading ◽  
Combined Loading ◽  
Impact Behavior ◽  
Rate Variation ◽  
Shear Stresses ◽  
Absorbed Energy ◽  
Static Compression ◽  
Rate Dependent ◽  
Dependent Behavior

Vinyl nitrile foams are polymeric closed-cell foam commonly used for energy absorption in helmets. However, their impact behavior has never been described in isolation. This study aims to characterize the strain rate dependent behavior of three VN foams in compression and combined compression and shear. Vinyl nitrile samples of density 97.5, 125, and 183 kg/m3 were submitted to quasi-static compression (0.01 s−1) and impacts in compression and combined compression and shear (loading direction of 45°). For impacts, a drop test rig was used, and a method was developed to account for strain rate variation during impactor deceleration. Young’s modulus and stress at plateau were correlated with foam density in both compression and combined loading. Vinyl nitrile foams were strain rate dependent: The absorbed energy at the onset of densification was two to four times higher at 100 s−1 than at 0.01 s−1. In combined loading, the compressive stress at yield was reduced by 43% at a high strain rate. Compared to expanded polypropylene, vinyl nitrile foams transmitted less stress at the onset of densification for equivalent absorbed energy and presented a larger ratio between the compression and shear stresses in combined loading (0.37 at yield). This larger ratio between the compression and shear stresses might explain why vinyl nitrile helmet liners are thought to be better at reducing head rotational acceleration than expanded polypropylene helmet liners.

Modeling and Testing Strain Rate-Dependent Tensile Strength of Carbon/Epoxy Composites

2007 ◽  
Vol 353-358 ◽  
pp. 1418-1421 ◽  
Author(s):  
Gui Ping Zhao ◽  
Zheng Hao Wang ◽  
Jian Xin Zhang ◽  
Qiao Ping Huang
Keyword(s):  
Tensile Strength ◽  
Strain Rate ◽  
Strain Rate Range ◽  
Split Hopkinson Tensile Bar ◽  
Rate Dependent ◽  
Dependent Behavior ◽  
Split Hopkinson ◽  
Rate Experiment ◽  
Epoxy Matrix Composite ◽  
Dependent Model

Tensile strength is an important material property and usually can be determined experimentally. The strain rate dependent behavior of T300 carbon/epoxy matrix composite was characterized over a wide strain rate range (10×10-5 s-1to10×104s-1). The low to moderate strain rate experiments were carried out on a MTS machine, while the high strain rate experiment was conducted with a split Hopkinson tensile bar. A rate dependent model was introduced to simulate the material response. Two kinds of stacking sequence of composite specimens [(45/-45)4]s and [(0/45/90/-45)2]s were tested at different strain rates, and the results were used to determine parameters of the model. The predictions of the model showed to agree fairly well with the experimental results. The tensile strength and initial elastic modulus of the composites increase when the strain rate increases.

scholarly journals A Methodology for Characterization of the Strain Rate-Dependent Behavior of PU Foam

2014 ◽  
Vol 7 (3) ◽  
pp. 514-519 ◽  
Author(s):  
N. Shivakumar ◽  
Anindya Deb ◽  
Clifford Chou ◽  
H. Chittappa
Keyword(s):  
Strain Rate ◽  
Rate Dependent ◽  
Pu Foam ◽  
Dependent Behavior

High-Velocity Impact of Carbon/Epoxy Composite Laminates

2007 ◽  
Vol 334-335 ◽  
pp. 73-76
Author(s):  
Gui Ping Zhao ◽  
Zheng Hao Wang ◽  
Jian Xin Zhang ◽  
Chong Du Cho
Keyword(s):  
Strain Rate ◽  
High Velocity ◽  
Composite Laminates ◽  
Epoxy Composites ◽  
High Velocity Impact ◽  
Velocity Impact ◽  
Rate Dependent ◽  
Dependent Behavior ◽  
Static Tensile ◽  
Split Hopkinson

The response of Carbon/epoxy composites under high velocity impact was investigated experimentally. The strain rate dependent behavior of T300 Carbon/epoxy matrix composite in tension is studied experimentally by split Hopkinson bar technique. Dynamic stress-strain plot was obtained and compared with the quasi-static tensile test results. The results of the study indicate that Carbon/epoxy composites are strain rate dependent materials. Stacking sequence has a significant effect on the material response. Tensile strength of the composites all increased with increasing strain rate. And failure strain decreased when strain rate increased.

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