Ultimate Strength Prediction of a Plenum Under Pressure Produced by Selective Laser Sintering

Ultimate Strength Prediction of a Plenum Under Pressure Produced by Selective Laser Sintering

 

Solvay Engineering Plastics, a global leader in advanced polyamide solutions, is the principal material sponsor for the Polimotor project, who aims at opening the way for a technological breakthrough in the automotive sector by replacing up to 10 metal parts by plastic materials in the engine Polimotor 2 engine.

 

Challenge

Due to the fact that parts are built of layer superposition without the need of support materials, laser sintering can quickly produce components that integrate complex internal features and functions. However the direction in which the part is built greatly affects the printed part strength. Although the printed material behavior is not affected by the building direction, its ultimate strength is reduced in the stacking direction.

 

Solution

 

• Create and calibrate the material behavior using the appropriate constitutive law. The glass beads are modelled using an elastic law while the pressure-dependent Drucker-Prager model is well suited to catch the matrix behavior.
• Fully characterize the failure surface using the appropriate failure criterion. The failure surface shape, specific to 3D printed material, can be well fitted with a generalized version of the Tsai-Wu transversely isotropic failure criterion.
• Perform a coupled MSC Marc/Digimat calculation to establish the ultimate pressure load the part is able to withstand.

 

Results/Benefits

 

• Precise description of the material behavior and failure surface
• Study sensitivity of the part strength to its orientation in the build chamber
• Avoid producing parts that do not meet the strength requirements by taking into account the specificity of 3D printing processes