本文選題：約束混凝土 + 空腔膨脹�。� 參考：《國防科學(xué)技術(shù)大學(xué)》2013年碩士論文

【摘要】：本文以新型遮彈結(jié)構(gòu)技術(shù)研究為背景,鑒于約束混凝土遮彈層結(jié)構(gòu)的潛在優(yōu)勢和現(xiàn)有研究的嚴(yán)重不足,開展了鋼管約束混凝土遮彈層結(jié)構(gòu)單元抗動能彈侵徹探索試驗(yàn)、數(shù)值模擬和理論分析,研究了鋼管約束混凝土的侵徹機(jī)理和抗彈機(jī)制,為約束混凝土遮彈技術(shù)的深入研究和推廣應(yīng)用提供了依據(jù)。本文主要創(chuàng)新性工作和成果如下:(1)改進(jìn)了現(xiàn)有不可壓縮理想彈塑性材料有限球形和柱形空腔膨脹理論�？紤]材料壓縮性和靶板側(cè)面自由邊界徑向位移的影響,建立了可壓縮理想彈塑性材料有限球形和柱形空腔膨脹理論。數(shù)值算例表明:當(dāng)彈性波未達(dá)到自由邊界時(shí),本文模型與無限空腔膨脹模型一致;彈性波到達(dá)自由邊界后,靶體進(jìn)入彈塑性階段,自由邊界位移影響較小,可以忽略;當(dāng)塑性區(qū)到達(dá)自由邊界后,邊界位移較大,不可忽略。(2)建立了約束混凝土有限球形和柱形空腔膨脹模型,得到了空腔壁壓力的理論解。數(shù)值算例表明:在膨脹初始階段,側(cè)向約束的影響較小,隨著膨脹過程的發(fā)展,側(cè)向約束可顯著提高空腔壁壓力;當(dāng)約束剛度較小時(shí),側(cè)向約束作用對空腔壁壓力的影響不明顯;而當(dāng)約束剛度較大時(shí),側(cè)向約束使空腔壁壓力明顯增大;但隨著約束剛度的進(jìn)一步提高,空腔壁壓力的提高幅度越來越小,存在合理的約束剛度和靶體半徑。(3)進(jìn)行了鋼管混凝土抗12.7mm穿甲彈單發(fā)和多發(fā)打擊試驗(yàn),得到了破壞模式及主要破壞參數(shù)。結(jié)果表明:鋼管約束混凝土在高速(800m/s以上)侵徹下,迎彈面形成了明顯的漏斗坑,核心混凝土側(cè)面形成了環(huán)向裂紋,背面混凝土出現(xiàn)了滑移;相對于半無限混凝土,鋼管約束混凝土的抗侵徹能力可提高15%以上,且具有較強(qiáng)的抗多發(fā)打擊能力。(4)侵徹試驗(yàn)、數(shù)值模擬和有限空腔膨脹理論相結(jié)合,分析了鋼管約束混凝土的抗侵徹能力和機(jī)理。結(jié)果表明:鋼管約束混凝土的抗侵徹能力優(yōu)于半無限混凝土,鋼管的約束作用可有效減小混凝土的損傷,提高抗多發(fā)打擊能力;提高側(cè)向約束剛度可有效提高約束混凝土的抗侵徹能力,合理采用較小的靶體尺寸可提高側(cè)向約束效應(yīng),減小混凝土損傷。
[Abstract]:In this paper, based on the research of new type of shielding structure, in view of the potential advantages of confined concrete barrier structure and the serious shortage of existing research, the exploration test of resistance to kinetic energy projectile penetration of steel tube confined concrete shell structure unit is carried out. Numerical simulation and theoretical analysis are carried out to study the penetration mechanism and anti-ballistic mechanism of confined concrete filled steel tube, which provides a basis for further research and application of confined concrete shielding technology. The main innovative work and results in this paper are as follows: (1) the theory of finite spherical and cylindrical cavity expansion of incompressible ideal elastoplastic materials is improved. Considering the influence of material compressibility and radial displacement of free boundary on the side of target plate, the expansion theory of finite spherical and cylindrical cavity of compressible ideal elastoplastic material is established. Numerical examples show that the present model is consistent with the infinite cavity expansion model when the elastic wave does not reach the free boundary, the elastic wave reaches the free boundary, the target enters the elastic-plastic stage, and the free boundary displacement has little effect, which can be neglected. When the plastic zone reaches the free boundary, the boundary displacement is large and can not be ignored. (2) the finite spherical and cylindrical cavity expansion model of confined concrete is established, and the theoretical solution of cavity wall pressure is obtained. Numerical examples show that the influence of lateral constraint is small in the initial stage of expansion. With the development of expansion process, lateral constraint can significantly increase the wall pressure of cavity, and when the constraint stiffness is small, The influence of lateral constraint on cavity wall pressure is not obvious, but when the constraint stiffness is large, the wall pressure increases obviously, but with the further improvement of constraint stiffness, the increase of cavity wall pressure becomes smaller and smaller. The single and multiple impact tests of concrete filled steel tube (CFST) against 12.7mm armour-piercing projectile were carried out with reasonable restraint stiffness and target radius. The failure mode and main failure parameters were obtained. The results show that under the penetration of steel tube confined concrete over 800 m / s at high speed, the projectile surface forms obvious funnel pits, the core concrete forms circumferential cracks on the side, and the back side concrete slips, compared with semi-infinite concrete, The penetration resistance of concrete confined by steel tube can be increased by more than 15%, and it has strong ability to resist multiple attack. The penetration test is carried out. The numerical simulation is combined with the theory of finite cavity expansion, and the ability and mechanism of resisting penetration of confined concrete filled steel tube are analyzed. The results show that the penetrability of steel tube confined concrete is better than that of semi-infinite concrete, and the constraint effect of steel tube can effectively reduce the damage of concrete and improve the ability of resisting multiple strikes. The anti-penetration ability of confined concrete can be effectively improved by increasing lateral restraint stiffness, and the damage of concrete can be reduced by reasonably adopting small target size.
【學(xué)位授予單位】：國防科學(xué)技術(shù)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2013
【分類號】：TU398.9;TJ410

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本文編號：1915227