Compliant flexural behaviour in laser sintered nylon structures: Experimental test and Finite Element Analysis – correlation

• We measured flexural properties of SLS specimens with standard geometries/methods.
• We designed two custom ridged patterns in SLS to tune stiffness according to shape.
• Parametrically ridged patterns showed variations in bending modulus and stiffness of nearly 70%.
• FEA experiments showed a high correlation with error levels below 20%.
• Functionally graded stiffness can be controlled by means of parametric features.

The aim of this paper is to present a simple and easily tuneable method of creating compact structures with gradient flexural properties using Selective Laser Sintering (SLS). The method makes use of a sine-wave ridged pattern commonly found in nature which produces a compliant bending pattern along various directions defined by the reference axes. These patterns have been adopted due to the ease with which it is possible to parametrically control the height, width, pitch and thickness of the designed structure. A series of 3-point bending tests and finite element analyses of flat and ridged specimens have been performed in order to obtain more appropriate material definition for the inclusion of such patterns into more complex structures.Results show that a parametrically defined ridged pattern has the ability to induce passive bending behaviour on structures. Differences in bending stiffness between 20% and 50% were observed for the directions parallel and perpendicular to the ridged pattern lines and a capacity to redistribute stresses across the bending specimen was highly dependent on the ridged pattern direction.