scholarly journals Effects of strain rate and bond preparation for dissimilar materials in energy dispersive applications

2021 ◽  
Vol 250 ◽  
pp. 01005
Author(s):  
Tom Commins ◽  
Clive R Siviour
Keyword(s):  
Composite Materials ◽  
Strain Rate ◽  
Energy Absorption ◽  
Dissimilar Materials ◽  
Polymer Interfaces ◽  
Ambient Conditions ◽  
Impact Speed ◽  
Projectile Impact ◽  
Gas Gun ◽  
Ceramic Bond

Composite materials, typically consisting of two or more dissimilar materials adhered together in layers, are frequently used for energy absorption applications. The interface and material characteristics strongly influence the global energy absorptive capability of the composite. This research focuses on ceramic-polymer interfaces and, in particular, links between the properties of the composite, the interface and the separate materials. After characterisation of the materials, the effects of impact speed and bond condition were considered for a polymer-ceramic bond in a threepoint bend configuration. Specimens were loaded in a screw-driven machine at 0.05 mm s-1 and through projectile impact at speeds of approximately 50 m s-1. Screw-driven experiments were performed at ambient and sub ambient conditions, with the temperature chosen to simulate the expected polymer performance in the gas gun experiment, making use of the equivalence of rate and temperature for polymers.

Energy Absorption at High Strain Rate of Magnesium Alloy AZ31B

2020 ◽  
Vol 12 (05) ◽  
Author(s):  
M. M. Mubasyir ◽  
◽  
M. F. Abdullah ◽  
K. Z. Ku Ahmad ◽  
R. N. R. Othman ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
High Strain Rate ◽  
Strain Rate ◽  
Energy Absorption ◽  
High Strain ◽  
Magnesium Alloy Az31b

scholarly journals Static Mechanical Properties of Expanded Polypropylene Crushable Foam

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 249
Author(s):  
Przemysław Rumianek ◽  
Tomasz Dobosz ◽  
Radosław Nowak ◽  
Piotr Dziewit ◽  
Andrzej Aromiński
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Strain Rate ◽  
Energy Absorption ◽  
Experimental Tests ◽  
Absorption Capacity ◽  
Strain Rates ◽  
Foam Density ◽  
Energy Absorption Capacity ◽  
Closed Cell

Closed-cell expanded polypropylene (EPP) foam is commonly used in car bumpers for the purpose of absorbing energy impacts. Characterization of the foam’s mechanical properties at varying strain rates is essential for selecting the proper material used as a protective structure in dynamic loading application. The aim of the study was to investigate the influence of loading strain rate, material density, and microstructure on compressive strength and energy absorption capacity for closed-cell polymeric foams. We performed quasi-static compressive strength tests with strain rates in the range of 0.2 to 25 mm/s, using a hydraulically controlled material testing system (MTS) for different foam densities in the range 20 g/dm3 to 220 g/dm3. The above tests were carried out as numerical simulation using ABAQUS software. The verification of the properties was carried out on the basis of experimental tests and simulations performed using the finite element method. The method of modelling the structure of the tested sample has an impact on the stress values. Experimental tests were performed for various loads and at various initial temperatures of the tested sample. We found that increasing both the strain rate of loading and foam density raised the compressive strength and energy absorption capacity. Increasing the ambient and tested sample temperature caused a decrease in compressive strength and energy absorption capacity. For the same foam density, differences in foam microstructures were causing differences in strength and energy absorption capacity when testing at the same loading strain rate. To sum up, tuning the microstructure of foams could be used to acquire desired global materials properties. Precise material description extends the possibility of using EPP foams in various applications.

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.

Energy absorption behaviour of different grades of steel sheets using a strain rate dependent constitutive model

2017 ◽  
Vol 111 ◽  
pp. 9-18 ◽  
Author(s):  
Pundan K. Singh ◽  
Anindya Das ◽  
S. Sivaprasad ◽  
Pinaki Biswas ◽  
Rahul K. Verma ◽  
...  
Keyword(s):  
Constitutive Model ◽  
Strain Rate ◽  
Energy Absorption ◽  
Steel Sheets ◽  
Rate Dependent

Experimental Investigation and Numerical Simulation of Porous Volcano Rock Hypervelocity Impact on Whipple Shield of Spacecrafts

2010 ◽  
Vol 452-453 ◽  
pp. 385-388
Author(s):  
Bin Jia ◽  
Gao Jian Liao ◽  
Hai Peng Gong ◽  
Bao Jun Pang
Keyword(s):  
Numerical Simulation ◽  
Space Debris ◽  
Geometrical Model ◽  
Hypervelocity Impact ◽  
Rear Wall ◽  
Projectile Impact ◽  
Gas Gun ◽  
Significant Damage ◽  
Speed Range ◽  
Whipple Shield

All spacecrafts in earth orbit are subject to hypervelocity impact by micro-meteoroids and space debris, which can in turn lead to significant damage and catastrophic failure of spacecraft. Porous volcano rock was adopted as one of micro-meteoroid material due to their similar physical and geometric features. Two-stage light gas gun experiments were carried out for a 6mm diameter volcano rock projectile impact on an Al-Whipple shield within the speed range from 1 km/s to 3 km/s. An ANSYS/LS-DYNA software was employed and justified by experimental results, in which a porous geometrical model was established for volcano rock projectile. The higher speed range was extended from 3 km/s to 10 km/s by numerical simulation. The results of experiments and numerical simulation indicated that major damage on rear wall of the Whipple shield impacted by volcano rock projectile is caused by the fragments of bumper of the shield, which is different from that of aluminum projectile. And 5.5km/s is the critical speed of a 6mm diameter volcano rock projectile impact on the Whipple shield investigated.

scholarly journals Dynamic properties of stainless steel under direct tension loading using a simple gas gun

2018 ◽  
Vol 183 ◽  
pp. 02035 ◽  
Author(s):  
Anatoly Bragov ◽  
Alexander Konstantinov ◽  
Leopold Kruszka ◽  
Andrey Lomunov ◽  
Andrey Filippov
Keyword(s):  
Stainless Steel ◽  
Strain Rate ◽  
High Speed ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Properties ◽  
Tensile Load ◽  
Hopkinson Pressure Bar ◽  
Direct Tension ◽  
Stress Strain ◽  
Gas Gun

The combined experimental and theoretical approach was applied to the study of high-speed deformation and fracture of the 1810 stainless steel. The material tests were performed using a split Hopkinson pressure bar to determine dynamic stress-strain curves, strain rate histories, plastic properties and fracture in the strain rate range of 102 ÷ 104 s-1. A scheme has been realized for obtaining a direct tensile load in the SHPB, using a tubular striker and a gas gun of a simple design. The parameters of the Johnson-Cook material model were identified using the experimental results obtained. Using a series of verification experiments under various types of stress-strain state, the degree of reliability of the identified mathematical model of the behavior of the material studied was determined.

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