<p>This study investigates the crashworthiness performance and deformation characteristics of 3D-printed polylactic acid (PLA) conical frusta with cutouts. We systematically varied four design parameters: half conical angle (0, 5, 10, and 15 degree), cutout diameter (4, 8, 12, and 16 mm), cutout number (2, 3, 4, and 5), and cutout location (20, 30, 40, and 50 mm). The printed structures were subjected to a quasi-static axial compression loading to evaluate their crush performance. Throughout the testing process, the crush force and energy absorption responses were recorded as a function of displacement. Additionally, the failure modes of the structures were carefully analyzed to identify the mechanisms of deformation. We evaluated crashworthiness using five key performance indicators: initial peak crush force <InlineEquation ID="IEq1"> <EquationSource Format="TEX">\(\left({\text{F}}_{\text{i}\text{p}}\right)\)</EquationSource> </InlineEquation>, total absorbed energy (U), mean crush force (<InlineEquation ID="IEq2"> <EquationSource Format="TEX">\({\text{F}}_{\text{m}}\)</EquationSource> </InlineEquation>), specific energy absorption (SEA), and crushing force efficiency (CFE). Furthermore, we applied the Complex Proportional Assessment (COPRAS) method to systematically identify the optimal design, which normalizes performance indicators and assigns weights reflecting their relative importance. The results show clear trends: increasing the conical angle reduces <InlineEquation ID="IEq3"> <EquationSource Format="TEX">\({\text{F}}_{\text{i}\text{p}}\)</EquationSource> </InlineEquation>, U, and <InlineEquation ID="IEq4"> <EquationSource Format="TEX">\({\text{F}}_{\text{m}}\)</EquationSource> </InlineEquation> but improves CFE. Compared with the baseline configuration (A0/D8/N3/L30), the optimal design A15/D8/N3/L30 (15° conical angle, 8 mm cutouts, three holes spaced 30 mm apart) reduced <InlineEquation ID="IEq5"> <EquationSource Format="TEX">\({\text{F}}_{\text{i}\text{p}}\)</EquationSource> </InlineEquation> by ~ 66%, U and <InlineEquation ID="IEq6"> <EquationSource Format="TEX">\({\text{F}}_{\text{m}}\)</EquationSource> </InlineEquation> by ~ 32%, while maintaining SEA essentially unchanged (− 0.05%), and doubled the CFE (+ 100%). This combination achieves the most balanced performance across all crushing metrics. Additionally, configurations with smaller cutout diameters or fewer cutouts tend to exhibit higher peak loads and greater energy absorption.</p>

Decision-guided design of 3D-printed PLA conical frusta under quasi-static axial loading

期刊论文
发表日期：

2026年5月8日

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Mahmoud M. Awd Allah,
Mahmoud F. Abd El-Halim,
Marwa A. Abd El-baky

摘要

This study investigates the crashworthiness performance and deformation characteristics of 3D-printed polylactic acid (PLA) conical frusta with cutouts. We systematically varied four design parameters: half conical angle (0, 5, 10, and 15 degree), cutout diameter (4, 8, 12, and 16 mm), cutout number (2, 3, 4, and 5), and cutout location (20, 30, 40, and 50 mm). The printed structures were subjected to a quasi-static axial compression loading to evaluate their crush performance. Throughout the testing process, the crush force and energy absorption responses were recorded as a function of displacement. Additionally, the failure modes of the structures were carefully analyzed to identify the mechanisms of deformation. We evaluated crashworthiness using five key performance indicators: initial peak crush force \(\left({\text{F}}_{\text{i}\text{p}}\right)\) , total absorbed energy (U), mean crush force ( \({\text{F}}_{\text{m}}\) ), specific energy absorption (SEA), and crushing force efficiency (CFE). Furthermore, we applied the Complex Proportional Assessment (COPRAS) method to systematically identify the optimal design, which normalizes performance indicators and assigns weights reflecting their relative importance. The results show clear trends: increasing the conical angle reduces \({\text{F}}_{\text{i}\text{p}}\) , U, and \({\text{F}}_{\text{m}}\) but improves CFE. Compared with the baseline configuration (A0/D8/N3/L30), the optimal design A15/D8/N3/L30 (15° conical angle, 8 mm cutouts, three holes spaced 30 mm apart) reduced \({\text{F}}_{\text{i}\text{p}}\) by ~ 66%, U and \({\text{F}}_{\text{m}}\) by ~ 32%, while maintaining SEA essentially unchanged (− 0.05%), and doubled the CFE (+ 100%). This combination achieves the most balanced performance across all crushing metrics. Additionally, configurations with smaller cutout diameters or fewer cutouts tend to exhibit higher peak loads and greater energy absorption.