中国塑料 ›› 2020, Vol. 34 ›› Issue (11): 59-65.DOI: 10.19491/j.issn.1001-9278.2020.11.011

• 加工与应用 • 上一篇    下一篇

熔融沉积PLA材料动态力学行为及本构模型研究

雷经发1,2, 魏展1,2, 刘涛1,2(), 孙虹1,2, 段焕天1,2   

  1. 1.安徽建筑大学机械与电气工程学院,合肥 230601
    2.工程机械智能制造安徽省教育厅重点实验室,合肥 230601
  • 收稿日期:2020-05-22 出版日期:2020-11-26 发布日期:2020-11-20
  • 基金资助:
    安徽省自然科学基金(1708085ME130);安徽高校优秀青年人才支持计划项目(gxyqZD2019057);安徽高校优秀拔尖人才培育资助项目(gxbjZD2020078);汽车噪声振动和安全技术国家重点实验室开放基金(NVHSKL-201407)

Dynamic Mechanical Behavior and Dynamic Constitutive Model of Fused Deposition PLA Materials

 LEI Jingfa1,2,WEI Zhan1,2, LIU Tao1,2(), SUN Hong1,2, DUAN Huantian1,2   

  1. 1.School of Mechanical and Electrical Engineering,Anhui Jianzhu University,Hefei 230601,China
    2.Anhui Key Laboratory of Intelligent Manufacturing of Construction Machinery,Hefei 230601,China
  • Received:2020-05-22 Online:2020-11-26 Published:2020-11-20
  • Contact: LIU Tao E-mail:tao.liu@ahjzu.edu.cn

摘要:

为分析低、高应变率下增材制造熔融沉积材料聚乳酸(PLA)的静、动态力学性能,利用万能材料试验机和分离式霍普金森压杆(SHPB)实验装置分别对3种打印速度(40、80、120 mm/s)的PLA材料进行加载应变率为0.000 5、1 000、1 500、2 000 s-1的静、动态力学性能测试,并观测了试样表面微观形貌。结果表明,PLA材料的弹性模量、屈服应力随应变率的增加而显著增加;微观形貌分析发现,打印速度为80 mm/s的材料缺陷较少,相同应变率下,该打印速度材料的弹性模量和屈服应力明显高于40 mm/s和120 mm/s 2种打印速度材料;静态载荷下,PLA材料会出现明显的弹性和塑性阶段,且塑性段呈现出了应变软化现象;动态载荷下,PLA材料具有显著的黏弹性特征,选取朱-王-唐(ZWT)模型建立了材料的黏弹性本构,该本构模型拟合曲线与实验曲线吻合较好。

关键词: 聚乳酸, 应变率, 分离式霍普金森压杆, 熔融沉积成型

Abstract:

To analyze the static and dynamic mechanical properties of an additive manufacturing fused deposition molding material, poly(lactic acid) (PLA), at low and high strain rates, MTS material testing machine and split Hopkinson pressure bar (SHPB) device were adopted severally to carried out the static and dynamic mechanical measurements at three printing speeds of 40, 80, and 120 mm/s under low-strain-rate and high?strain?rate loading conditions. The surface morphology of the prepared specimens was also observed. The results indicated that the elastic modulus and yield stress of PLA increased significantly with an increase of strain rate. Microscopic morphological analysis indicated that the PLA material exhibited fewer defects at a printing speed of 80 mm/s. At the same strain rate, the elastic modulus and yield stress of the material obtained at this printing speed were significantly higher than those at the printing speeds of 40 and 120 mm/s. The PLA material presented obvious elasticity and plasticity stages under the static load, and the plastic segment exhibited a strain-softening phenomenon. On the other hand, the PLA material showed significant viscoelastic characteristics under the dynamic load. The ZWT model was used to establish the viscoelastic constitutive model for the PLA material, and the fitting curve obtained from this constitutive model was in good agreement with the experimental curve.

Key words: poly(lactic acid), strain rate, split Hopkinson pressure bar, fused deposition molding

中图分类号: