销轴连接的铸钢件接触承压试验研究

Experimental study on steel casting with pin connection under contact pressure

对销轴连接的铸钢件承载能力进行试验研究。试验选择100、150、182 mm三种不同厚度的铸钢试件,最大加载拉力为8 000 k N。结果表明:在拉力作用下,铸钢试件发生了不同程度的塑性变形,塑性区面积随试件厚度的增大而显著减小,塑性开展大致呈剪切型发展。铸钢件与销轴直接承压接触的部位,由于应力集中很快达到屈服;接触变形导致区域内应力重分布,部分测点应变减小,甚至出现拉压应变反转的现象。与有限元分析结果对比表明,偏心受力会使铸钢件与销轴接触部位在加载初期产生较大应力集中。将承载力的试验结果与采用各国规范设计公式计算的结果进行对比,建议承载力计算公式中设计强度提高系数取为1.2。

Experimental study on the steel casting with pin connection was carried out. Castings with three different thicknesses of 100,150 mm and 182 mm were tested and the maximum tensile force was 8 000 kN. Results show that there are plastic deformations in different degrees on castings and the area of plastic zone which is roughly shear type decreases significantly with the increase of specimens＇ thickness. Due to stress concentration the area where casting and pin contact directly yields quickly. The contact deformation results in stress redistribution. Then the strains of some gauges decrease and tension and compression strains are even reversed. Comparison with FEA results shows that there is a great stress concentration where casting and pin contact in early stage of loading when steel casting is under eccentric force. Results of design formulas of different countries＇ standards are compared with the test results and the recommended value of the strength amplification factor is 1.2.