钢桥塔内部通行孔选型及有限元分析

钢桥塔内部通行孔对受压壁板力学性能产生不利影响。基于有限元分析,研究不同孔洞形状和孔洞大小对单轴受压开孔板弹性应力分布、弹性屈曲和弹塑性屈曲三方面性能的影响。结果表明:除圆孔外的其他各种孔型板,孔洞形状对开孔板弹性屈曲应力和弹塑性极限强度影响不大,但其对应力集中系数影响较大,其中,圆角矩形孔、长圆形孔和椭圆形孔板的应力集中系数较低。实际情况中,圆角矩形孔和长圆形孔板是钢桥塔内部通行孔的首选。但当孔径较大时,应采取孔洞补强措施来保证大孔径板件的力学性能满足设计要求。

ACCESS HOLE SHAPE SELECTION AND FINITE ELEMENT ANALYSIS OF PERFORATED PLATES IN STEEL PYLONS

The mechanical behaviors of compression plates in steel pylons are deteriorated by access holes. Based on finite element analysis, the influences of hole shape and hole size on stress concentration, elastic buckling, and elasto-plastic buckling of perforated plates under uniaxial compression are studied. Results show that elastic buckling stresses and elasto-plastic ultimate strengths of perforated plates containing various shapes of holes are of little variation except circular hole, while shapes of holes greatly affect the stress concentration factors, the stress concentration factors plates containing rectangular holes with circular corners, slotted holes as well as ellipse holes are significantly smaller than those of plates with other holes. Combined with practices, rectangular hole with circular corners and slotted hole are the best choices for access holes of the compression plate in steel pylon, and some strengthening methods should be adopted to ensure that the mechanical behaviors of perforated plates with large holes meet the design requirements when the diameter of the hole is big.