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一、前言铁路货车极易由其零部件中的交变应力引起损坏。这些交变应力的产生是由于轨道的几何条件,特别是由于轨道的不平顺引起的。在正常运行条件下,产生的应力在允许的极限之内,交变应力的循环是导致破坏的主要因素。每一应力循环在相应的零件中产生一定程度的损伤。这种损伤累积直到疲劳破坏的产生。这时,累积损伤达到一临界水平。了解货车这个特点并计算这个临界水平是货车“安全运行”设计的必不可少的部分。
I. INTRODUCTION Railway freight cars are easily damaged by alternating stresses in their parts. These alternating stresses are due to the geometric conditions of the orbit, especially due to the irregularities in the orbit. Under normal operating conditions, the stress generated is within the allowable limits, and the cycling of alternating stress is the main factor leading to the damage. Each stress cycle creates a degree of damage in the corresponding part. This damage accumulates until fatigue breaks down. At this point, cumulative damage reached a critical level. Understanding the characteristics of a truck and calculating this critical mass is an essential part of the truck’s “safe operation” design.