Design and Analysis of the Impact of Ultraviolet Aging on the Mechanical Properties and Durability of PLA Lattice Structures

Abstract

This study explores the design and performance evaluation of PLA (Polylactic acid) lattice structures, with a focus on understanding the eventuality of UV (Ultraviolet) radiation exposure on their mechanical properties. Utilizing Siemens NX software, a 40mm cubic lattice structure with 8mm squared perforations, was designed for optimal performance. With the use of compressive tests, the properties and structural integrity of the 3D printed lattice structures of 50.4% porosity were put to the test. Comprehensive analysis of the stress-displacement data revealed critical insights into the modes of failure as they were aged. Results indicated that short wave UV exposure of wavelength between 365 to 295 nm increased the brittleness of the PLA structures, as evidenced by higher Young's modulus and enhanced compressive strength over time. However, prolonged aging also led to increased displacement on the maximum compressive force from 2.72mm to 3.21mm and compressive strain at the maximum compressive force from 6.81% to 8.02%, suggesting progressive material deterioration. Findings from this study add to a deeper perception of the behavior of PLA under accelerated testing, simulating environmental effects, informing future design and material selection for improved durability and performance in engineering applications. This study provides an understanding of the performance of PLA under UV exposure, contributing to the development of more sustainable additive manufacturing materials, as the findings highlighted the need for careful consideration of the effects UV aging in the design and application of PLA lattice structures.