A multidisciplinary method for simulation guided design of mechanical structures

Composite sandwich panels are often used in aerospace industry for their high bending stiffness to weight ratio and high vibration damping capacity. Use of sustainable materials for skins and core of sandwich panels have recently attracted researchers’ attention since structural, vibrational, environmental, and economic aspects should be considered in the design process. This work presents a multidisciplinary method for simulation guided design of mechanical structures by mainly focusing on vibro-acoustic performance of sandwich floor slabs used in aircrafts. Vibration behaviour of the slab strongly depends on the geometry, material properties (Young’s modulus, density, damping), and boundary conditions. Python programming language is used to fully parameterize the structure, to automate the multiphysics analysis, and to develop a user interface for practical use. It allows combining the computer aided design scripting, finite element software scripting, numerical calculations and postprocessing features. Numerical simulation is performed to estimate the natural frequencies and mode shapes of the complex floor slab geometry. Harmonic analysis is performed to determine the forced vibration response. Acoustic radiated power is deduced from the velocity continuity of the elastic surface and the acoustic particles on the surface. The acoustic radiated power and acoustic intensity of the slab geometry are computed using the elementary radiators method. Numerical simulation is also performed to estimate the structural stresses and deflections. The introduced multidisciplinary and parameterized approach allows to determine the main design parameters to guide the engineers with minimum prototyping efforts. The method allows quick sensitivity analysis of design parameters (material, geometry, joint and fixing locations, etc.) as well as the modification of multiple parameters at once. A good preliminary design can significantly reduce the time and cost spent in the structural design process. By considering all major aspects of the design (structural, vibration, environmental, cost, etc.) from the beginning of the design, exchanges between different departments and unexpected surprises during a project can be minimized. Furthermore, once the model, analyses and postprocessing are automated behind a user-friendly interface, the introduced physics-based tool can be used by design engineers who are not necessarily experts in simulations.