摘要
假定木梁和纤维增强聚合物(FRP)布分别服从标准线性固体黏弹性本构和弹性本构,且FRP布与木梁紧密粘贴,建立了FRP布加固黏弹性矩形截面Timoshenko木梁弯曲变形的控制方程.在此基础上,利用Laplace变换及其逆变换,给出了突加集中和均布载荷作用下FRP布加固简支黏弹性Timoshenko木梁弯曲变形的轴向位移、转角和挠度解析表达式.根据花旗松(DF)木材标准线性固体本构的材料参数,数值分析了芳纶纤维聚合物(AFRP)含量和梁跨高比对AFRP布加固黏弹性Timoshenko DF梁弯曲蠕变行为的影响.结果表明:Timoshenko DF梁的弯曲蠕变效应显著,AFRP布加固可有效减小Timoshenko DF梁的蠕变挠度;随着DF梁跨高比减小或AFRP含量的提高,AFRP布加固Timoshenko DF梁的最大压应力和最大拉应力减小.
Assuming timber beam and fibre reinforced polymer （FRP） sheet following the standard linear solid constitutive relation of viscoelasticity and elasticity, respectively, and tight bonding between the FRP sheet and timber beam surface, the governing equation for bending deformation of the rectangular cross-section Timoshenko timber beam reinforced with FRP sheet was established. Then, with the Laplace transform and its inverse transform, the analytical expressions of the axial displacement, the rotation angle and the deflection of the bending deformation of the simply-supported FRP sheet- reinforced beam subjected to a step concentrated or an uniform load were presented. Based on the material parameters of the Douglas-fir （DF） timber, the influences of volume fraction of ararnid fibre reinforcement polymer （AFRP） and the span-depth of the beam on the creep bending of the FRP sheet- reinforced DF beam were analyzed numerically. It is revealed that the creep bending effect of the Timoshenko DF beam is remarkable, and the creep deflection can be effectively decreased by the AFRP sheet reinforcement. Furthermore, with decrease of the span-depth of the DF beam or the increase of the AFRP volume fraction, the maximum compressive and tensile stresses of the AFRP-reinforced Timoshenko DF beam can be decreased.
出处
《力学季刊》
CSCD
北大核心
2017年第1期70-80,共11页
Chinese Quarterly of Mechanics
