Study on the bending and failure behaviour of wooden sandwich panels with corrugated core, randomized gaps, and wood defects

The environmental issue in engineering approaches is critical due to the requirements of the circular economy. The main emphasis in this work was the experimental and numerical investigation method of wooden sandwich structures' bending characteristics with the corrugated core. It included the effect of natural, randomized gaps in veneer. In addition, the influence of the re-bending of the damaged beam on its mechanical properties was also investigated. The results show that beams are an excellent construction material. The modulus of elasticity of the beams, till failure, ranged from 1580 to 3247 MPa, and the bending strength from 3.3 MPa to 7.9 MPa. In the second bending test, these values decreased after revealing new cracks in the core. It has been shown that the greater the share of gaps, the lower the modulus of elasticity of the beams, the lower the strength, and the lower the value of the destructive force of the beam. Numerical calculations showed that the virtual beam model without imperfections and gaps was characterized by a maximum force of 11.5 % higher than the best beam with imperfections and gaps. The prepared numerical model correctly determined the damage in the core and confirmed its applicability in engineering practice.