作　　者： (欧阳煜）; (江勇）; (周磊）;

机构地区： 上海大学土木工程系,上海200444

出　　处： 《上海大学学报（自然科学版）》 2017年第4期609-622,共14页

摘　　要： 将木梁视为服从标准线性固体本构的黏弹性体,假定纤维增强聚合物(fiber reinforced polymer,FRP)布与木梁紧密粘贴,研究了FRP布加固木梁线性弯曲的蠕变行为.在建立FRP布加固黏弹性矩形截面木梁弯曲变形控制方程的基础上,利用Laplace变换,给出了突加均布载荷作用下FRP布加固简支黏弹性木梁弯曲的解析解.根据相关试验数据,确定了花旗松(Douglas-fir,DF)木梁标准线性固体本构的材料参数,分析了芳纶纤维增强塑料(aramid FRP,AFRP)布含量和梁跨高比等对AFRP布加固简支DF木梁弯曲变形的影响.结果表明:AFRP布加固可有效减小木梁的蠕变挠度;随着DF木梁蠕变的增加,AFRP布加固DF木梁的中性轴逐渐靠近粘贴AFRP布的侧边,且随着DF木梁跨高比或AFRP布含量的提高,AFRP布加固DF木梁的最大压应力和最大拉应力减小. Regarding timber beam as a viscoelastic medium with a standard linear solid constitutive relation, and assuming bonding tightly between the fiber reinforced polymer （FRP） sheet and timber beam, the creep behavior of linear bending of the timber beam rein- forced with FRP sheet is studied. Based on the established governing equation for bending deformation of the viscoelastic rectangular cross-section timber beam reinforced with FRP sheet, ananalytical solution of bending of the simply-supported FRP-reinforced viscoelastic timber beam subject to step uniform load is presented by using Laplace transform. The material parameters of the standard linear solid constitutive relation for Douglas-fir （DF） timber are determined with existing experimental data. The influences of volume fraction of aramid FRP （AFRP） sheet and span-depth ratio of beam on the bending behavior of the simply-supported DF timber beam reinforced with AFRP sheet is analyzed numerically. It is shown that creep deflections of the DF timber beam can be effectively decreased by AFRP sheet reinforcement. With development of creep of the DF timber beam, the neutral axis of the DF timber beam reinforced with AFRP sheet moves to the edge of the timber beam of bonding AFRP sheet. Furthermore, with increase of the span-depth ratio of DF timber beam and volume fraction of AFRP sheet, maximum compressive and tensional stresses of the AFRP-reinforced DF timber beam decrease.

关 键 词： 纤维增强聚合物 加固 木梁 黏弹性 解析解