Experimental and numerical modeling of shear behavior of laminated Guadua bamboo for different fiber directions

The shear strength and the crack pattern of laminated Guadua bamboo (LGB) are studied in this work, by means of both experimental tests and numerical simulation, considering the three different orthogonal directions of the fibers: (i) when the fiber is parallel to the loading direction, (ii) when the fiber is perpendicular to the loading direction without crossing the reduced area plane, and (iii) when the fiber is perpendicular to the loading direction and crossing the reduced area plane. The slats orientation and disposition in LGB were experimentally studied, when the contact surface between slats is parallel to the reduced area plane and when it is perpendicular. Likewise, the cases when the contact surface between slats matches with the reduced area plane is tested and when it is not. The numerical model of finite elements is based on the continuum strong discontinuity approach for composite materials and the Weibull probability model for the failure progressive of fibers. The crack direction obtained in the numerical simulation is approximately equal to the one observed in the corresponding experimental test, regardless of the disposition slats. LGB with fibers parallel to the loading direction exhibits a crack that matches with the reduced area plane. In LGB with fibers perpendicular to the loading direction that do not cross the reduced area plane, the crack is inclined 45 degrees with respect to loading direction. In LGB with fibers perpendicular to the loading direction and crossing the reduced area plane, several cracks are made up perpendicularly to loading direction and parallel to the fiber orientation.