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对于低强度钢大型焊接结构灾难性破坏的一般方式-解理(脆性)断裂,已经作过广泛的研究。然而,除了对很高强度钢外,研究者们通常却几乎没有注意到由剪切(塑性)方式导致结构破坏这类严重问题。采用高强度材料制成的结构(火箭壳体),在接近屈服点加载的条件下的验证试验中,就发生过包括有“低能剪切”破裂情况的破坏。对于预计会出现大量塑性超载的使用场合,则采用低能剪切材料可同能发生局部脆性破坏的材料一样极其危险。本研究旨在研定一个用来评定屈服强度范围为100～150KSi的钢在爆炸加载情况下的撕裂特征的试验方法。本研究创立了一种新的爆炸撕裂试验方法。其初步结果证明,各种高强度材料的撕裂抗力是有很大差别的。本文考察了V型却贝平台水平与撕裂抗力间的关系。在爆炸撕裂试验中,V型却贝平台水平显著地低于40～50英尺-磅则伴随有低能剪切特征。然而,高强度钢的V型却贝平台水平与撕裂抗力之定量关系要较原先预期的复杂得多。此外,还对包括有屈服强度依从因素和其他一些因素在内的种种复杂性进行了讨论。看来,除了本报告所叙述的初步探讨外,有必要对各种因素作广泛深入的研究。
Extensive research has been conducted on the general mode of catastrophic failure of large, low-strength steel welded structures, such as cleavage (brittle) fractures. However, except for very high strength steels, researchers often fail to notice the serious problems of structural failure caused by shear (plastic) methods. Structures made from high-strength materials (rocket housings) have undergone failures including “low-energy shear” fractures in verification tests near loading. For applications where a large amount of plastic overload is expected to occur, the use of a low energy shear material can be as extremely hazardous as a material that can be locally brittle. The purpose of this study was to develop a test method for assessing the tearing characteristics of steels with yield strengths in the range of 100-150 ksi under explosive loading. This study created a new method of explosion tear test. The preliminary results show that the tear resistance of various high-strength materials is very different. This paper examines the relationship between the V-type platform level and tear resistance. In explosive tearing tests, the V-Trump platform is significantly below 40 to 50 feet-lbs with low energy shear characteristics. However, the quantitative relationship between level and tearing resistance of high-strength steels is much more complex than originally anticipated. In addition, the complexity of yield strength compliance and other factors is discussed. It seems that, in addition to the initial discussions described in this report, it is necessary to make a comprehensive and in-depth study of various factors.