Research Of Equivalent Elastic Constants Of Corrugated Board

Corrugated board is widely used in the packaging fields. Its small weight and good rigidity is its merit. The analysis of mechanical properties of corrugated sandwich structure is becoming a more important problem, as the engineering application of sandwich structures. In this study, a computation method of equivalent elastic constants of single corrugated board for U corrugated cardboard is researched.There are no corrugated structural shells in universal finite element programs such as ANSYS, so the corrugated structural analyses can be conducted in special way instead of in direct way. Based on existing basic theories, corrugated board equivalent model of core level flexible rigidity is proposed. The corrugated board is equivalent to an orthotropic homogeneous lamina, at the same time, the equivalent young's modulus in the MD and the CD, the shear stiffness and the flexural rigidity are calculated. The concrete steps as follows: first, every equivalent elastic constant of the core is calculated, then the equivalent elasticity constants of the whole corrugated sandwich structure are researched by means of the mixed law, at the same time, every equivalent elastic constant is calculated by two practical examples.There are two mode of operations, in this text, APDL is used to model and simulate. The single corrugated board is no-linear, so the single corrugated board modeling is built and emulated by APDL of ANSYS, then tension test is performed in the MD and the CD and the shear test is carried. In the simulation, setting constraints and applying load are the key, the result of the simulation is distortion and strength, the results are converted strain and stress, at last, according to Hooke's law, elastic constants are received. At last, compared the result of the simulation with the result of calculation, the theoretical results are decided to be right. The flexural rigidity is verified referring the result of NORDSTRAND's three-point bend test.First the corrugating medium is equivalent to a constant thickness anisotropic homogenous board and the equivalent calculation is obtained for getting the equivalent parameters, then the mixed law is used to be equated the equivalent core with the fluting.In this text, the equivalent method can be used in practical engineering designing by comparing and judging the error and this method is reasonable.