Mechanical behavior of beams with variable stiffness obtained by 3D printing

Laszlo Racz,Mircea Cristian Dudescu

doi:10.1051/matecconf/202134308014

Abstract

Additive manufacturing or 3D printing gained a widespread popularity in recent years due to the ability of the method to manufacture components with high geometrical complexity. The most cost-effective process to manufacture plastic parts using 3D printing is the fused deposition modeling (FDM) method. Process parameters as the infill rates but also the printed pattern of different layers and their orientation have a significant influence on the mechanical properties of specimens fabricated by FDM. Controlling the process parameters is possible to generate materials with variable mechanical proprieties. The paper presents the analysis of a beam with constant cross-section but variable stiffness. Variable stiffness is achieved by changes in different cross-sections of the beam of the infill rates of the printing process. The mechanical behavior consisting of force-displacements curves is analyzed by three-point bending tests of variable stiffness samples and comparison with similar beams having constant infill rate. The results consist of E-modulus variation, maximum force and deflection curve. Analytical calculations and finite element analyses are employed to predict the mechanical behavior of the specimens printed with variable infill rate. The obtained results proved the concept of equal stress-beam with constant cross-section obtained by 3D printing process parameters variation.

Highlights

Additive manufacturing and 3D printing gained a widespread popularity in recent years due to the ability of the method to manufacture components with high geometrical complexity
The obtained results revealed that raster angle and raster width have the greatest effect on the flexural properties of the material, the paper presenting the optimal levels of the process parameters
For our study we proposed to analyze the effect of infill rate on 3D printed part printed with 0o direction and variable infill rate

Summary

Introduction

Additive manufacturing and 3D printing gained a widespread popularity in recent years due to the ability of the method to manufacture components with high geometrical complexity. The most cost-effective process to manufacture plastic parts using 3D printing is the fused deposition modeling (FDM) method. The mechanical behavior of the 3D printed parts is influenced by infill pattern in combination with the infill rate. To exploit the full potential of creating customized internal structures in 3D printed parts according to load distribution, a suitable modeling method should be established. With this procedure it would be theoretically possible to create parts with optimum dimensions in terms of geometrical shape and optimized internal structure. For our study we proposed to create a test specimen, to study the influence of the variable infill on the mechanical behavior of the 3D printed part

Sample manufacturing

Experimental study

Finite Element analysis

Analytical calculation

Findings

Conclusions