Low Temperature Effects on E-glass/Urethane Composite Materials at High Strain Rates

Author(s):  
Shunjun Song ◽  
Jack Vinson ◽  
Roger Crane
AIAA Journal ◽  
2004 ◽  
Vol 42 (5) ◽  
pp. 1050-1053 ◽  
Author(s):  
Shunjun Song ◽  
Jack R. Vinson ◽  
Roger M. Crane

Author(s):  
Shunjun Song ◽  
Jack R. Vinson

Composite materials are used in a wide variety of low temperature applications because of their unique and highly tailorable properties. These low temperature applications of composites include their use in Arctic environments and most of them involve dynamic loads, for example, spacecraft applications where they use cryogenic engines, hypervelocity impact situations at very high altitudes, civil engineering applications in extreme cold regions, and offshore structures in cold regions. The U.S. Navy stated that under certain conditions naval vessels might encounter strain rates up to 1200/sec. Because the dynamic properties of composite materials may vary widely with both strain rates and temperature, it is important to use the dynamic properties at the expected temperatures when the loading conditions involve high strain rates and extreme temperatures. Very few materials have been characterized at high strain rates even at room temperature. Still less effort has been spent in trying to model the high strain rate properties to develop a predictive capability at room temperature. It has been hoped that earlier modeling for metals, such as Johnson and Cook [1], and Zerilli and Armstrong [2] might be used for composite materials. The Johnson-Cook model was modified by Weeks and Sun [3] for composite materials. Other recent modeling research has been performed by Theruppukuzki and Sun [4], Hsiao, Daniel and Cordes [5] and Tsai and Sun [6]. Woldesenbet and Vinson [7] have characterized the high strain rate and fiber orientation effects on one typical graphite/epoxy composite. Most of these characterizations model ultimate strengths only.


2018 ◽  
Vol 183 ◽  
pp. 02021 ◽  
Author(s):  
Ahmed Elmahdy ◽  
Patricia Verleysen

The design of sample geometries and the measurement of small strains are considered the main challenges when testing composite materials at high strain rates using the split Hopkinson bar technique. The aim of this paper is to assess two types of tensile sample geometries, namely dog-bone and straight strip, in order to study the tensile behaviour of basalt fibre reinforced composites at high strain rates using the split Hopkinson bar technique. 2D Digital image correlation technique was used to study the distribution of the strain fields within the gauge section at quasi-static and dynamic strain rates. Results showed that for the current experiments and the proposed clamping techniques, both sample geometries fulfilled the requirements of a valid split Hopkinson test, and achieved uniform strain fields within the gauge section. However, classical Hopkinson analysis tends to overestimate the actual strains in the gauge section for both geometries. It is, therefore, important to use a local deformation measurement when using these 2 geometries with the proposed clamping technique.


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