Abstract: The superstructure of the 8×4 lightweight urban dump truck is investigated as the research object, undergoing structural rigidity and strength verification analysis using finite element analysis methods under typical operating conditions such as lifting, turning, and twisting. The results indicate that when fully loaded with 50 t, the dump body experiences significant overall deformation and exhibits high-stress regions under various conditions, posing risks of bulging failure and yield failure. Under lifting conditions, the maximum equivalent stress in the front region of the under frame exceeds the allowable stress, the structural strength fails to meet design requirements. Combined analysis results, optimizations are implemented on both the dump body and under frame through structural improvements and dimensional adjustments. The maximum deformation of the dump body is reduced from 52.2 mm to 14.8 mm, and the maximum stresses of both the dump body and under frame generally within the allowable stress range. The optimized superstructure of the dump truck meets the corresponding rigidity and strength requirements.

Key words: dump truck; dump body; under frame; finite element analysis; structural optimization

摘要： 以 8×4 轻量化城市渣土车上装为研究对象，分别在举升、转弯和扭转等典型工况下， 利用有限元分析方法对其进行结构刚强度校核分析。结果表明，在满载 50 t 时，厢体在多种 工况下整体变形较大且存在部分高应力区域，有胀厢失效和屈服失效风险；底架在举升工况 下，前端区域最大等效应力超过了许用应力，结构强度无法满足设计要求。结合分析结果， 通过改进结构和调整尺寸分别对厢体和底架进行了优化，厢体变形由最大 52.2 mm 降为 14.8 mm，厢体与底架最大应力总体上也在许用应力范围内，优化后的渣土车上装达到了相应 刚强度要求。

关键词: 渣土车；厢体；底架；有限元分析；结构优化