“多次冲击抗力理论”,是西安交大自1958年开始研究的。历来沿用的理论认为:在设计和制造各种机械时,有些零、部件,必需选用“冲击韧度”高的材料。冲击韧度是根据一次冲击确定的,即是看要以多大力量,才能一下子把材料撞裂。金属材料有这样的特性,韧度高,强度就比较低。如果又要韧度高,又要强度大,那就只好多用些钢铁,于是设计出来的机器又重又大。实际上,除了各种装甲车或一些军事设施,容易在炮弹打击下,受很大的冲力,一次打穿之外,绝大部分机械和零、部件,都是受较小的力量,经过千万次冲击才断裂的。例如各种枪枝上的枪机撞针,凿岩机的活塞,铆钉枪上的铆钉窝,锻锤的锤杆、锻模以及空气压缩机的阀片等等,都是如此。西安交大,从这个事实出发,研究用多次冲击法,来测定钢材能耐多大的冲击力。经过大量试验,发现了新的规律:冲击韧度高、强度低的材料,在多次冲击下,寿命并不长;反之强度高、冲击韧度低的材料,却往往远优于冲击韧度高的材料。按旧的理论那样,牺牲强度去追求较高的韧度,并不必要,甚至适得其反。他们把这个新理论,称为“多次冲击抗力理论”。按照这个新理论来设计机器,有些原来要用合金钢,优 “Multiple Impact Resistance Theory”, Xi’an Jiaotong University since 1958 began to study. The theory has always been used that: In the design and manufacture of various machinery, some zero, parts, must choose the “impact toughness” high material. Impact toughness is based on an impact to determine, that is, to see how much power to crack the material at once. Metal materials have such characteristics, high toughness, strength is relatively low. If you have to tough high, but also strength, it would only have to use more steel, so the design of the machine again heavy. In fact, apart from all kinds of armored vehicles and some military installations, they are easily hit by shells. They are subject to a great deal of impulse and a puncture. Most machinery, parts and components are subject to minor forces. After tens of millions The impact was only broken. For example, a variety of firearms on firearms striker, rock drill piston, rivet rivets on the rivets, hammer forging hammer, forging dies and air compressor valves and so on, are so. Xi’an Jiaotong University, starting from this fact, the study used multiple impact method to determine how much impact the steel can withstand. After a large number of tests and found a new law: high impact toughness, low strength materials, under many impacts, life expectancy is not long; the contrary, high strength, low impact toughness of the material, but often far superior to the impact toughness High material. According to the old theory, it is not necessary or even counterproductive to sacrifice strength to pursue higher tenacity. They called this new theory “multiple impact resistance theory.” According to this new theory to design the machine, some of the original use of alloy steel, excellent