Analytical Approach to Predict Pre–Camber Deflection of the Pre-stressed Glulam Beams

Buan Anshari




Abstract


A new approach to reinforce glulam timber beams using compressed wood (CW) has been developed by the Author. The compressed wood blocks are inserted into pre-cut holes on the top of glulam beams to produce pre-camber and to generate initial tensile and compressive stresses on the top and on the bottom extreme fiber of the glulam beam, respectively. A simple analytical approach has been developed to predict pre-camber deflections of the beams reinforced with three CW blocks. Assuming that moisture-dependent expansion of the CW block creates an interactive linear pressure between the glulam beam and the CW block, this would generate a pair of eccentric force away from the neutral axis of the beam. It is shown that the pre-camber deflection predicted at midspan of the short beams with various reinforcing arrangements give good agreement with the measured pre-camber from previous experimental results.


Keywords


Compressed wood (CW); CW reinforced glulam beam; pre-stressed; pre-camber.

References


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  6. Anshari, B., Guan, Z.W, and Komatsu, K., Finite Element Modeling of the Pre-camber of Glulam Beams Reinforced by Compressed Wood, The Proceeding of the 11th World Conference on Timber Engineering (WCTE), Riva del Garda, Trentino, Italy, June 20-24, 2010.
  7. Anshari, B. and Guan, Z.W., Numerical Modelling of the Initial Stress and Upward Deflection of Glulam Beams Pre-Stressed by Compressed Wood, Applied Mechanics and Materials, 493, 2014, pp. 408-413.
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