A review of impact testing on marine composite materials: Part IV – Scaling, strain rate and marine-type laminates

2018 ◽  
Vol 200 ◽  
pp. 929-938 ◽  
Author(s):  
L.S. Sutherland
Keyword(s):  
Composite Materials ◽  
Strain Rate ◽  
Impact Testing ◽  
Marine Composite

scholarly journals Rate Dependent Multicontinuum Progressive Failure Analysis of Woven Fabric Composite Structures under Dynamic Impact

2004 ◽  
Vol 11 (2) ◽  
pp. 103-117 ◽  
Author(s):  
James Lua ◽  
Christopher T. Key ◽  
Shane C. Schumacher ◽  
Andrew C. Hansen
Keyword(s):  
Composite Materials ◽  
Strain Rate ◽  
Dynamic Loading ◽  
Damage Model ◽  
Woven Fabric ◽  
Loading Conditions ◽  
Rate Dependent ◽  
Fabric Composite ◽  
Dynamic Loading Conditions ◽  
Marine Composite

Marine composite materials typically exhibit significant rate dependent response characteristics when subjected to extreme dynamic loading conditions. In this work, a strain-rate dependent continuum damage model is incorporated with multicontinuum technology (MCT) to predict damage and failure progression for composite material structures. MCT treats the constituents of a woven fabric composite as separate but linked continua, thereby allowing a designer to extract constituent stress/strain information in a structural analysis. The MCT algorithm and material damage model are numerically implemented with the explicit finite element code LS-DYNA3D via a user-defined material model (umat). The effects of the strain-rate hardening model are demonstrated through both simple single element analyses for woven fabric composites and also structural level impact simulations of a composite panel subjected to various impact conditions. Progressive damage at the constituent level is monitored throughout the loading. The results qualitatively illustrate the value of rate dependent material models for marine composite materials under extreme dynamic loading conditions.

Aspects of Strain Rate Effects on Some Composite Materials

2000 ◽  
Author(s):  
Emmanuel O. Ayorinde
Keyword(s):  
Acoustic Emission ◽  
Composite Materials ◽  
Strain Rate ◽  
Matrix Cracking ◽  
Epoxy Composites ◽  
Fiber Architecture ◽  
Strain Rate Effects ◽  
Rate Effects ◽  
General Strain ◽  
Ultrasonic Images

Abstract Effects of moderate straining speed on the material and damage characteristics of beam samples of graphite/epoxy and E-glass/epoxy composites were investigated. The basic fiber architecture utilized was unidirectional, axial layup, but data was also obtained for the 45-degree orientation. Ultrasonic and acoustic emission (AE) inspections were utilized. The acoustic emission records show matrix cracking. The ultrasonic images revealed the regions of failure. The results show that in general, strain rate notably affects material and damage properties.

Micro Impact Testing of Lead Free Solder Joints

2008 ◽  
Vol 32 ◽  
pp. 99-102
Author(s):  
Ranjan Rajoo ◽  
Erich H. Kisi ◽  
D.J. O'Connor
Keyword(s):  
Solder Joint ◽  
High Strain Rate ◽  
Strain Rate ◽  
High Strain ◽  
Intermetallic Layer ◽  
Displacement Transducer ◽  
Impact Testing ◽  
Lead Free ◽  
Linear Variable Displacement Transducer ◽  
Free Solder

This paper presents data obtained from a newly-developed instrument to test the quality of solder interconnections at high strain rate – the ‘micro-impactor’. This shear test of the interconnection at high strain rate mimics the stress experienced by the solder joint when undergoing shock due to drop-impact. Instrumented with a load cell and linear variable displacement transducer (LVDT), it also has the ability to provide dynamic impact force and displacement data. Earlier concepts to characterise the solder joint at high strain rates such as the miniature pendulum impact tester [1] lacked this capability. This micro-impactor was used to study the effect of increasing silver (Ag) and copper (Cu) concentration in solder alloys on the shear strength of the solder joint. The performance of these lead-free alloys was also compared to that of the well-established leaded solder. It was found that increasing the silver content increases the yield strength of the solder, causing the failure to occur at the brittle intermetallic layer instead of in the bulk of the solder.

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