Analysis On The Reaction Of Visco Multilayer Shell Under Impact Load

Structures which composed of multilayer shells containing visco-elastic parts,say, solid-propulsers, KE projectiles, etc, play an important role in area of civil useand national defence. In these implementations, the transient response of dynamicstresses are usually much higher than those obtained by quasi-static analysis whensubjected to different kinds of impact loads, thus making dynamic analysis on suchsituations much more important.The responses of visco-elastic multilayer shell subjected to step inner pressurewas studied under the assumption of plain strain state and compared with the resultsof numerical simulation. In this way, the feasibility of using FEM to study suchproblems was verified. Based on this verification, a typical multilayer structurecomposed of shell, heat insulating layer, lining layer and propellant was studied withFEM software when subjected to inner pressure load, the mechanics of lining layerwas emphasized. Some influencing factors of the stress, such as artificialdelamination layer model, thickness of lining layer, visco-elasticity of the materialwas discussed.In addition, a semiempirical formula which was derived from the cavityexpansion theory and empirical formula was established to determine thepenetrating resistance of a KE projectile when penetrating a concrete target. What’smore, the former derived penetrating resistance was adopted as the equivalent loadto simulate the transient response of a KE projectile which contained visco-elasticpropellant. The influence of visco-elasticity, like viscosity term, elasticity term andrelax time, on the stress response was studied and the influence rule was discussed.