FRP加固轴心受压木柱应力-应变模型  

STRESS-STRAIN MODEL FOR FRP-STRENGTHENED WOOD COLUMN UNDER AXIAL COMPRESSION

作　　者：邵劲松[1] 刘伟庆[1] 蒋桐[1] 王曙光[1] 周叮[1] 

机构地区：[1]南京工业大学土木工程学院,南京210009

出　　处：《工程力学》2008年第2期183-187,共5页Engineering Mechanics

基　　金：国家重大基础项目前期研究专项(2002CCCD1700)

摘　　要：在Tsai-Wu强度准则的基础上,建立了三向受压木柱的屈服准则及随后的屈服面发展方程。根据内力平衡和应变相容的原理,提出了FRP加固木柱轴心受压时的增量应力-应变关系模型。提供了12根CFRP和GFRP环向加固木柱的轴心抗压性能试验数据。计算结果和试验数据比较表明,在达到加固木柱极限抗压强度之前两类结果吻合较好,而之后计算结果明显偏高。试件的工作机理表明,在达到加固木柱极限抗压强度时,环向受拉FRP中的应变很小,远小于其极限抗拉应变。此外,提出了加固木柱与极限抗压强度相对应的环向应变计算公式,并将之用于计算模型程序运算的结束条件。根据Bazan-Buchanan准则,将加固木柱极限抗压强度之后的σ1-ε1曲线简化为下降的直线,与试验结果吻合较好。提出模型可用于进行工程分析和设计。Based on Tsai-Wu criterion, the plastic yielding formulation and the corresponding yielding-surface equation of triaxially compressed wood columns are developed. From the equilibrium condition of external forces and the strain compatibility, an elasto-plastic incremental model has been presented to describe the stress-strain relationship when the FRP-strengthened wood column is uniaxially compressed. The experiments of the uniaxially compressed columns circumferentially wrapped by CFRP or GFRP sheets have been performed for 12 different strengthening cases. It is shown that experiment data and corresponding analytical results are consistent before the strengthened column reaches its ultimate compressive strength. However, the analytical predictions are higher than the experimental results when the stress in the member exceeds its ultimate compressive strength. It is observed from the experiments that the hoop tensile strain is small and far less than the ultimate tensile strain when the strengthened wood column reaches its compressive strength. Moreover, based on the experimental data, the formula to predict the hoop strain of strengthened columns at ultimate compressive strength is formulated and it can be used as the close condition in the interactive procedure of the numerical model. According to the Bazan-Buchanan criterion, the σ1-ε1 curve beyond the ultimate compressive strength is simplified as a declined straight line, which corresponds to the experimental results well. So the proposed model can be applied to the engineering design.

关 键 词：木柱 加固 受压 FRP 应力-应变模型 极限抗压强度 

分 类 号：TU366.2[建筑科学—结构工程]