Abstract Experimental studies are conducted to investigate the implosion characteristics of thin cylindrical aluminium-alloy tubes. The effects of various parameters that generate different responses on the implosion behaviours are investigated. Aluminium-alloy tubes are fabricated from a 6061-T6 material and designed in the range of 2.5–6.7 length-to-diameter ratios; wall thickness-to-diameter ratios are varied from 55 to 69. The geometric imperfection parameters, defined as the initial ovality and thickness unevenness, are considered. Two different pressurising media, i.e., water only and the combination of water and nitrogen gas are employed. In addition small- and medium-sized of pressure chamber are utilised to clarify the pressure drop after the ultimate strength reached. Furthermore, non-linear finite element analyses, benchmarked for quantitative validation and comparison of the imploded tubes, are conducted. The numerical benchmark quantities are initial ovality, thickness unevenness, and air-backed fluid cavity parameters. The results of these experiments indicated that the effects of combined water and nitrogen can reproduce a constant pressure environment similar as actual undersea conditions, but the combined pressuring media can reduce the pressuring rate.

中文翻译：

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薄圆柱铝合金管内爆特性的实验研究

摘要 通过实验研究了薄圆柱形铝合金管的内爆特性。研究了产生不同响应的各种参数对内爆行为的影响。铝合金管由 6061-T6 材料制成，设计的长径比范围为 2.5-6.7；壁厚直径比从 55 到 69 不等。几何缺陷参数，定义为初始椭圆度和厚度不均匀度，被考虑在内。采用两种不同的加压介质，即仅水和水和氮气的组合。另外利用中小型压力室澄清达到极限强度后的压降。此外，非线性有限元分析，对内爆管进行定量验证和比较。数值基准量是初始椭圆度、厚度不均匀度和气垫流体腔参数。这些实验的结果表明，水和氮结合的影响可以再现与实际海底条件相似的恒压环境，但结合加压介质会降低加压速率。