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挖掘机是一种在土石开挖等方面具有不可替代作用的重要工程设备,核心部件质量诊断、智能化及整机轻量化是其发展的三大主要方向。针对钢板平直度对挖掘机工作臂焊接质量存在重要影响的问题,在传统辊式矫直理论的基础上,依据三点弯曲理论、板材变形特点及分层理论建立板材矫直过程中的应力中性层偏移量计算模型,从理论上证明中性层偏移现象的存在以及它与反弯半径、板材厚度及材质的关系。通过室温拉伸试验得到高强钢板Q690的力学性能以此作为模型构建的参数基础;再结合弯曲试验研究矫直过程中性层偏移规律,得到中性层偏移值与反弯半径的变化关系。在本课题组多辊矫直机试验平台上对中性层偏移理论进行验证,结果表明考虑中性层偏移的Q690钢板平直度小于1 mm/m。
Excavator is an important engineering equipment that plays an irreplaceable role in excavation of earth and rock. The quality diagnosis, intelligence and overall weight reduction of the core components are the three main directions of its development. Aiming at the problem that flatness of steel plate has an important influence on welding quality of working arm of excavator, based on the traditional theory of roller straightening, the stress of plate straightening process is established based on three-point bending theory, deformation characteristics of plate and stratification theory Neutral layer offset calculation model, theoretically proves the existence of neutral layer offset phenomenon and its relationship with the bending radius, sheet thickness and material. The mechanical properties of high strength steel Q690 were obtained at room temperature by tensile test, which was used as the parameter basis for the model construction. Combined with the bending test, the displacement law of the neutral layer in the straightening process was studied, and the relationship between the neutral layer offset and the bending radius was obtained . The neutral layer migration theory was verified on the multi-roller leveler test platform in this project. The results show that the straightness of Q690 steel plate with neutral layer offset is less than 1 mm / m.