Journal of Shanghai University(Natural Science Edition) ›› 2017, Vol. 23 ›› Issue (4): 609-622.doi: 10.12066/j.issn.1007-2861.1664

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Analytical solution of bending of viscoelastic timber beam reinforced with fiber reinforced polymer sheet

OUYANG Yu, JIANG Yong, ZHOU Lei   

  1. Department of Civil Engineering, Shanghai University, Shanghai 200444, China
  • Received:2015-09-07 Online:2017-08-30 Published:2017-08-30

Abstract:

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 reinforced 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.

Key words: analytical solution, reinforcement, timber beam, viscoelasticity, fiber reinforced polymer (FRP)