CAJ | 학술논문

利用LS-DYNA有限元软件模拟弹体撞击作用下平纹织物的动态过程,分析织物断裂前的变形特性以及能量吸收特性,讨论边界约束条件和弹体形状对织物动态响应的影响.结果表明:纱线应变能和纱线动能是弹体动能转变的最主要形式,在给定计算的时间内,对于四边无约束、对边同定约束和四边固定约束3种边界条件,不论弹头形状采用平头、半球头和卵形头中的哪一种,两者之和占弹体动能损失量的比例不小于74.6%.模拟结果还表明.边界约束条件和弹体形状对织物的变形、应力分布以及能量吸收特性均有明显影响.边界条件不同,纱线动能和纱线应变能占弹体动能损失量的比例会发生较大变化,织物的能量吸收特性也不同.弹体头部形状不同,受撞击区影响的纱线数目也不同,弹头越钝,织物中抽拔出的纱线数目越多.从织物结构的抗弹性能角度看,织物结构抗钝头弹体的穿透能力要优于尖头弹体.
이용LS-DYNA유한원연건모의탄체당격작용하평문직물적동태과정,분석직물단렬전적변형특성이급능량흡수특성,토론변계약속조건화탄체형상대직물동태향응적영향.결과표명:사선응변능화사선동능시탄체동능전변적최주요형식,재급정계산적시간내,대우사변무약속、대변동정약속화사변고정약속3충변계조건,불론탄두형상채용평두、반구두화란형두중적나일충,량자지화점탄체동능손실량적비례불소우74.6%.모의결과환표명.변계약속조건화탄체형상대직물적변형、응력분포이급능량흡수특성균유명현영향.변계조건불동,사선동능화사선응변능점탄체동능손실량적비례회발생교대변화,직물적능량흡수특성야불동.탄체두부형상불동,수당격구영향적사선수목야불동,탄두월둔,직물중추발출적사선수목월다.종직물결구적항탄성능각도간,직물결구항둔두탄체적천투능력요우우첨두탄체.
A commercially available finite element analysis code, LS-DYNA, is used to model the dynamic responses of a patch of plain-woven fabric under ballistic impact of projectile. The fabric deformation and time history of energy absorption mechanism before yams rupture were investigated by numerical simulation method, and effects on the fabric dynamic responses by boundary conditions and projectile shapes were also discussed. The simulation results showed that the yarn strain energy and the yarn kinetic energy were the dominant energy transfer of kinetic energy of projectile. At a given time, for the three boundary conditions with four edges free, two edges clamped and four edges clamped, the sum of yarn strain energy and kinetic energy accounted not less than 74.6% for different shaped projectile with flat, hemispherical or ogival nose. Simulation results also indicated that the boundary conditions and projectile shapes significantly affected the fabric deformation, stress distribution and time history of energy absorption mechanism. The yam strain energy and the yam kinetic energy changed the proportion in loss of projectile kinetic energy due to the different boundary conditions. The nose shape of projectile had an effect on the number of yams that was involving in the impact region. For the bulletproof performance of plain-woven fabric, the blunt nosed projectile was more difficult to perforate the fabric architecture than sharp nosed one.