考虑P△效应的体外预应力梁的M-φ分析法  

ANALYSIS OF DP EFFECT OF EXTERNALLY PRESTRESSED BEAMS BY THE METHOD OF M-φ RELATIONSHIP

作　　者：方德平[1] 

机构地区：[1]华侨大学土木工程系,福建泉州362011

出　　处：《工程力学》2002年第4期113-117,共5页Engineering Mechanics

摘　　要：本文推导了T型截面梁的弯矩-轴力-曲率关系,提出了分析大偏心体外预应力筋的应力增量和梁弯曲性能的通用方法。在本方法中,体外筋的效应表示为作用在转向座和锚具处的等效荷载,梁(不含体外筋)的内力是由外荷载和等效荷载共同引起的。把静定梁的变形曲线简化为由单元节点位移所组成的多边形,把DP效应的附加弯矩转化为节点上的集中力,较方便地考虑了这一效应。比较荷载作用前后,转向座和锚具的变形差,计算出体外筋的应变和应力。因此这一方法考虑了体外筋的变形协调条件,同时自动地考虑了体外筋偏心距的损失。计算结果与文献[2,4]相吻合。In this paper, the M-N-f relationship of a T-shaped beam section and the calculation of the externally prestressed tendon抯 deformation with large eccentricities are studied. A general method for analyzing the stress increment of external tendon and flexural behavior of beam is presented. In this method, the action of external tendon is expressed as the equivalent loads applying at the deviators and anchorage ends. The beam excluding external tendon is subjected to bending moment and axial force caused by both applied loads and equivalent loads. The DP effect is regarded as the forces applying at the nodes of the elements by simplifying the deflection curve into polygon in statically determinate beam. By comparing the different positions of deviators and anchorage ends before and after loading, the force of external tendon is obtained, the deformation compatibility of the external tendon is met, and the loss of tendon's eccentricity is considered automatically. The numerical results agree well with the experimental results.

关 键 词：M-φ分析法 体外筋 预应力梁 P△效应 弯矩-轴力-曲率 大偏心 抗弯强度 变形协调 等效荷载 

分 类 号：TU323.3[建筑科学—结构工程]