Effect of heat treatment on the blast loading response of combined geometry shell core sandwich structures

Abstract

a b s t r a c tThe effect of heat treatment on the dynamic crushing and energy absorption behavior of combined geometry shell cores (hemisphere and cylinder) of sandwich structures were investigated both experimentally and numerically. The applied heat treatment on the combined geometry shell cores relieved the stress caused by deep drawing, diminishing the peak transmitted forces. The verified numerical models of the as-received and heat-treated combined geometry shells were used to model blast loading of various sandwich configurations and the additional sandwich configurations of reversing the cylindrical side of the cores to the impacted side. Both the applied heat-treatment and the reversing process decreased the magnitude of the force transmitted to the protected structure. The applied heat treatment increased the arrival time of blast force wave to the protected structure, while the reversing resulted in opposite.

Investigation of penetration behavior of combined geometry shells at quasi-static and intermediate strain rates: An experimental and numerical study

“…The static and dynamic friction coefficients at all contacts were taken 0.3 and 0.2, respectively. The aforementioned values were also used in previous studies for the static and dynamic compression numerical models of the same core unit [23][24][25], and a good consistency between the experimental and numerical results was noted. As the penetration problems involve a high amount of plastic deformation and tearing, numerical model requires the optimization of contact and mesh sizes, mesh sensitivity analyses were conducted for each penetrator type.…”

“…Thus, in the next step, penetration into the sample containing residual stresses and strains in the penetration numerical model was performed. The details of the numerical deep drawing process were given previously in [23][24][25]. The combined geometry shells were modeled using the Johnson-Cook (JC) material flow stress model given as [27]…”

“…It is expected from an armor structure to withstand both of these threats. In this study, the penetration/perforation behavior of a core material with previously determined [23][24][25] static and dynamic crushing characteristics was investigated both experimentally and numerically. In addition to determining the energy absorption characteristics of such structures, which protect against blast by absorbing energy, it is also very important to examine the penetration and perforation behavior of the structures against pointed or blunt shrapnel like geometries that occur during explosion.…”

The effect of geometrical parameters on blast resistance of sandwich panels—a review

“…Since these materials have high impact resistance, the blast response of sandwich panels with FML face sheets showed higher blast resistance than traditional sandwich panels [13]. It was also stated in the literature that heat treatment to a part relieved the stress due to related manufacturing process and consequently reduced the blast load transmitted to back face sheet [14]. Apart from changing the material of front and back face sheets, some researchers investigated the effect of addition of a plate of different material between face sheets and core section of sandwich panels on blast response.…”