Modified split Hopkinson pressure bars for dynamic bending and shear tests

2006 ◽  
Vol 134 ◽  
pp. 725-730 ◽  
Author(s):  
A. Pignon ◽  
G. Mathieu ◽  
S. Richomme ◽  
J. M. Margot ◽  
F. Delvare
Keyword(s):  
Shear Tests ◽  
Split Hopkinson ◽  
Split Hopkinson Pressure Bars ◽  
Dynamic Bending

Effect of Material Composition on Impact Energy Absorbing Capability of Composite Laminates

2016 ◽  
Vol 715 ◽  
pp. 147-152
Author(s):  
Ryota Haruna ◽  
Takayuki Kusaka ◽  
Ryota Tanegashima ◽  
Junpei Takahashi
Keyword(s):  
Impact Loading ◽  
Composite Laminates ◽  
Fiber Type ◽  
Material Composition ◽  
Control Technique ◽  
Dynamic Stress Field ◽  
Split Hopkinson ◽  
Split Hopkinson Pressure Bars ◽  
Crushing Behavior ◽  
Energy Absorbing

A novel experimental method was proposed for characterizing the energy absorbing capability of composite materials during the progressive crushing process under impact loading. A split Hopkinson pressure bars system was employed to carry out the progressive crushing tests under impact loading. The stress wave control technique was used to avoid the inhomogeneity of dynamic stress field in the specimen. The progressive crushing behavior was successfully achieved by using a coupon specimen and anti-buckling fixtures. With increasing strain rate, the absorbed energy during the crushing process slightly decreased, whereas the volume of the damaged part clearly increased regardless of material type. Consequently, the energy absorbing capability decreased with increasing loading rate. The effects of material composition, such as fiber type, matrix type and fabric pattern, on energy absorbing capability were also investigated by using the proposed method.

scholarly journals Impact Perforation of aluminum Cymat Foam

2018 ◽  
Vol 183 ◽  
pp. 01003
Author(s):  
Ibrahim Elnasri ◽  
Han Zhao
Keyword(s):  
Impact Loading ◽  
Failure Strain ◽  
Failure Criteria ◽  
Tensile Failure ◽  
Static Test ◽  
System A ◽  
Split Hopkinson ◽  
Clamping System ◽  
Split Hopkinson Pressure Bars ◽  
Force Displacement

The behavior of aluminum Cymat foam under impact perforation loading was studied using experiments and simulations. Measurements at 40 m/s were performed with an inverse perforation setup using a Split Hopkinson Pressure Bars system. Such measurement is missing in a classical free-flying penetrator–immobile–target scheme under impact loading and makes it possible to directly compare impact the perforation force–displacement curves with the static ones. Compared with quasi-static test perforation forces obtained under the same geometry and clamping system, a significantly enhanced perforation force was found under impact loading. Numerical simulations of the perforation test were developed using LS-DYNAfinite element code to provide the local information necessary to understand the unexpected enhancement in perforation force. The shock effect was found to be responsible for enhancement of the perforation force and revealed that the honeycomb model with appropriate tensile failure criteria was more suitable for model perforation of the foam than the Deshpande and Fleck model with volumetric failure strain criteria

scholarly journals High Strain Rate Characterization of Shock Absorbing Materials for Landmine Protection Concepts

2003 ◽  
Vol 10 (3) ◽  
pp. 179-186 ◽  
Author(s):  
Jennifer McArthur ◽  
Christopher Salisbury ◽  
Duane Cronin ◽  
Michael Worswick ◽  
Kevin Williams
Keyword(s):  
Strain Rate ◽  
High Strain ◽  
Dynamic Testing ◽  
Stress Wave Propagation ◽  
Published Data ◽  
Split Hopkinson ◽  
Split Hopkinson Pressure Bars ◽  
Dynamic Material Properties ◽  
Foamed Metals

Numerical modelling of footwear to protect against anti-personnel landmines requires dynamic material properties in the appropriate strain rate regime to accurately simulate material response. Several materials (foamed metals, honeycombs and polymers) are used in existing protective boots, however published data at high strain rates is limited.Dynamic testing of several materials was performed using Split Hopkinson Pressure Bars (SHPB) of various sizes and materials. The data obtained from these tests has been incorporated into material models to predict the initial stress wave propagation through the materials. Recommendations for the numerical modeling of these materials have also been included.

Capture of Shear Crack Propagation in Metallic Glass by High-Speed Camera and In Situ SEM

2014 ◽  
Vol 626 ◽  
pp. 162-170 ◽  
Author(s):  
Bing Hou ◽  
Meng Zhao ◽  
Pei Yang ◽  
Yu Long Li
Keyword(s):  
Metallic Glass ◽  
High Speed ◽  
Shear Crack ◽  
Shear Bands ◽  
High Temporal Resolution ◽  
High Speed Camera ◽  
Stress Curve ◽  
Split Hopkinson ◽  
Split Hopkinson Pressure Bars

The dynamic double-notched experiments by using Split Hopkinson Pressure Bars (SHPB) and high-speed camera were performed on bulk metallic glass. In the double-notched experiment, shear crack propagating process was captured with the high temporal resolution of high-speed camera and the crack front propagating velocity was estimated to be 1137m/s. the shear strain/shear stress curve of BMG under dynamic loading was also obtained. Static in-situ SEM tensile experiments were included to study the multiple shear bands propagating behavior on a glassy ribbon. It was found that shear bands propagates progressively in an intermittent and discontinuous manner, and the choice of which shear bands to propagate and which ones to keep still among multiple shear bands is quite stochastic. This is explained qualitatively from the view point of energy.

A Numerical Investigation into the Tensile Split Hopkinson Pressure Bars Test for Sheet Metals

2013 ◽  
Vol 421 ◽  
pp. 464-467 ◽  
Author(s):  
Thanh Nam Pham ◽  
Hyo Seong Choi ◽  
Jong Bong Kim
Keyword(s):  
Flow Stress ◽  
High Strain Rate ◽  
Strain Rate ◽  
High Strain ◽  
Finite Element Analyses ◽  
Compressive Flow ◽  
Design Guide ◽  
Split Hopkinson ◽  
Split Hopkinson Pressure Bars

Determination of theflow stress of materials at high strain rate is very important in automotive and military areas.The compressive flow stress at high strain rate can be obtained relativelyexactly by SHPB(Split Hopkinson Pressure Bars) tests. However, it is difficult to determinethe flow stressexactlyin the tensile state by using the SHPB tests. The difficulty in the tensile SHPB tests is how to fix a specimen on two bars. So, the design of a specimen and holders is needed to obtain more accurate measurement of the flow stress. In this study, the accuracy of the tensile SHPB tests results was numerically investigated. Finite element analyses of the tensile SHPB were carried out for various cases of fixing bolt location and bolting force. From the analysis results, a design guide for the fixing structure was obtained and the causes of error were investigated.

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