Development of a Constitutive Model to Predict the Elasto-Plastic Behaviour of 3D-Printed Thermoplastics: A Meshless Formulation

Author(s):  
Daniel Rodrigues ◽  
Jorge Belinha ◽  
Renato Natal Jorge ◽  
Lúcia Dinis
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Kaiyang Zhu ◽  
Zichen Deng ◽  
Shi Dai ◽  
Yajun Yu

Purpose This study aims to focus on the effect of interlayer bonding and thermal decomposition on the mechanical properties of fused filament fabrication-printed polylactic acid specimens at high extrusion temperatures. Design/methodology/approach A printing process, that is simultaneous manufacturing of contour and specimen, is used to improve the printing accuracy at high extrusion temperatures. The effects of the extrusion temperature on the mechanical properties of the interlayer and intra-layer are evaluated via tensile experiments. In addition, the microstructure evolution affected by the extrusion temperature is observed using scanning electron microscopy. Findings The results show that the extrusion temperature can effectively improve the interlayer bonding property; however, the mechanical properties of the specimen for extrusion temperatures higher than 270°C may worsen owing to the thermal decomposition of the polylactic acid (PLA) material. The optimum extrusion temperature of PLA material in the three-dimensional (3D) printing process is recommended to be 250–270°C. Originality/value A temperature-compensated constitutive model for 3D printed PLA material under different extrusion temperatures is proposed. The present work facilitates the prediction of the mechanical properties of specimens at an extrusion temperature for different printing temperatures and different layers.


Author(s):  
Zhe Chen ◽  
Ruishen Lou ◽  
Danming Zhong ◽  
Rui Xiao ◽  
Shaoxing Qu ◽  
...  

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1327
Author(s):  
Bo Pu ◽  
Wenbin Li ◽  
Qing Zhang ◽  
Yu Zheng ◽  
Xiaoming Wang

In this paper, the plastic flow and fracture behavior of 3D-printed Ti6Al4V (TC-4) alloy under different temperatures (289–1073 K) and strain rates (0.1–4100 s−1) were studied by using the MTS comprehensive experimental machine (MTS) and split Hopkinson pressure bar (SHPB) equipment. The patterns of the influence of temperature and strain rate on the plastic flow behavior of 3D-printed materials in different printing directions were analyzed and compared with those of the traditional TC-4. Based on the experimental data, the modified Johnson–Cook (J-C) constitutive model of 3D-printed TC-4 alloy was established, and the plastic deformation behavior of the material driven by detonation was studied by X-ray photography. The research results showed that under static loading conditions, the strength of the material (AM-P-TC-4) along the printing direction was much higher than the strength of the material perpendicular to the printing direction (AM-T-TC-4). However, there was no difference in material strength for different directions under dynamic loading. Second, under the same deformation conditions, the strength of the 3D-printed TC-4 alloy was considerably higher than that of the traditional TC-4 alloy, but adiabatic shear fracture could be more easily induced under dynamic compressive deformation conditions for the 3D-printed TC-4 alloy, and its fracture strain was substantially less than that of TC-4 alloys. The modified J-C constitutive model established in this paper could better describe the plastic flow behavior of the AM-P-TC-4 alloy under high temperature and high-strain rate deformation conditions.


2022 ◽  
Vol 316 ◽  
pp. 125819
Author(s):  
Hailong Wang ◽  
Jianwen Shao ◽  
Jing Zhang ◽  
Daoqin Zou ◽  
Xiaoyan Sun

Sign in / Sign up

Export Citation Format

Share Document