Calculating the displacement of the cross-sectional neutral axis of LVL sengon.

Sengon (Paraserianthes falcataria) laminated veneer lumber is an engineered wood product that uses multiple layers of thin sengon veneers assembled with adhesives. Made under controlled circumstances, this type of lumber is just as strong as conventional types of lumber commonly used as construction materials. Lumber has greater tensile strength than compressive strength. However, upon being put under a bending test, the fracture point happens to be on the tension area. It happens on the tension area suspected because of the displacement of the neutral axis from the cross-sectional weight axis. Therefore, this research was carried where a LVL sengon wood were imposed with a flexural load. The flexural test data from the strain gauge will be used in the calculation analysis by making a numerical simulation of the flexural stress-strain diagram and by applying the balance conditions of the forces worked on the beam. The numerical simulation of flexural stress-strain diagram will use the MATLAB program. From this calculation, the theoretical and experimenral neutral axis displacement will be obtained. From the laboratory test and the numerical simulation, the position of the experimental neutral axis tends to rise across the center of gravity of the beam as the load increases. While, in the theoretical calculation, the displacement of the neutral axis tends to go downward, but the neutral axis remains above the weight axis of the cross-section. The difference between the experimental and theoretical results is that several factors are not calculated in the theoretical calculation, for example, a shear force that occurs due to bending load, physical wood condition based on where it grows, the strength of wood fiber, etc. From the laboratory test and the running program that has been carried out, it can be concluded that the value of the stress-strain in the properties test can be used to predict the displacement of the neutral axis that happened in the bending test. [ABSTRACT FROM AUTHOR]