Theoretical and experimental considerations on the neutral axis of wood beams with a hole in different locations.

Holes contribute to the non-homogeneous nature of solid wood and shift the neutral axis of wood beams away from the centroid. Based on the plane-section assumption and idealized trapezoidal distribution, new calculating formulas will be presented in terms of the location of neutral axis for clear beams and wood beams with a hole at the center, compression zone and tension zone. To verify the results of theoretical analysis and formulas, four-point bending experiments of wood beams were performed by a digital image correlation (DIC) technique. There is a reasonable agreement between calculated and experimental results with a hole at the center or in the compression zone of the beams. Concerning a hole in the tension zone, on the other hand, the calculated locations of neutral axis are not in agreement with the experimental results, due to the plastic behavior on both the compression and tension zones of the beams in the inelastic stage. [ABSTRACT FROM AUTHOR]