冲击载荷下泵车底架结构疲劳累积损伤试验研究

Experimental study on fatigue cumulative damage of truck mounted concrete pump’s base frame under impact load

针对泵车底架长期处于高应力幅值的交变冲击载荷下,结构产生疲劳破坏从而引发泵车倾翻的安全问题,基于随机变幅载荷下结构疲劳累积损伤理论,提出了基于有限元分析与应力试验的结构设计,以及基于全工况随机载荷谱采集处理与疲劳累积损伤试验验证评估技术的精细耐久性设计验证方法,通过底架结构应力试验与疲劳试验进行试验验证。泵车底架结构可靠,结构件平均首次故障方量大幅提升,疲劳寿命达到12.6 a,相比实际服役车辆工业考核,对产品的抗疲劳性能进行验证评估的试验周期缩短30%以上,为底架系统的减振、结构优化、提升焊接结构抗疲劳和耐久性设计水平,提供了理论与试验依据。

Aiming at the long-term high stress amplitude of the truck mounted concrete pump’s base frame under the alternating impact load,the structure generates fatigue damage and causes the safety of the pump to tip over,based on the theory of fatigue cumulative damage under random variable amplitude load,the structural design based on finite element analysis and stress test,and the fine durability design verification method based on the random load spectrum of the whole working condition treatment and the fatigue cumulative damage test verification and evaluation technology are proposed,verified by the stress test and fatigue test of the base frame structure:the pump chassis structure is reliable,the average number of first failures of structural parts is greatly improved,and the fatigue life is up to 12.6 years.Compared with the actual service vehicle industry assessment,the test period for verifying the fatigue resistance of the product is shortened by more than 30%,which provides theoretical and experimental basis for vibration reduction,structural optimization of the base frame system and improvement of the design level of the anti-fatigue and durability design level of the welded structure.