3D打印连续纤维增强树脂T型梁的弯曲性能

Flexural Properties of 3D Printed Continuous Fiber Reinforced Resin T-beams

1中国机械科学研究总院集团有限公司先进成形技术与装备国家重点实验室,北京1000482清华大学机械工程系,北京1000843南京航空航天大学机电学院,南京210016实现基梁于结熔构融的沉轻积量技化、术功的能连化续设纤计维和增制强造树。脂本3D工作打对印筋工高艺0为m梁m结与构5的m制m造的提T供型了梁一打种印新件的在途不径,同该打工印艺参具数有下快的速弯近曲净性成能型进、行可测设计试性实强验,等研优究势了,能打够印基于熔融沉积技术的连续纤维增强树脂3D打印工艺为梁结构的制造提供了一种新的途径,该工艺具有快速近净成型、可设计性强等优势,能够实现梁结构的轻量化、功能化设计和制造。本工作对筋高0 mm与5 mm的T型梁打印件在不同打印参数下的弯曲性能进行测试实验,研究了打印厚度分别为0.7 mm、0.8 mm、0.9 mm时与打印丝束间距分别为0.6 mm、0.7 mm、0.8 mm时T型梁对应的弯曲强度与模量。由于3D打印连续纤维增强树脂材料存在着复杂的破坏模式,本研究运用声发射技术对T型梁的弯曲破坏过程进行测试分析,采用主成分分析法与K-means++聚类算法对采集的过程信号进行损伤分类。结果表明,当打印层厚为0.7~0.9 mm时,随着打印层厚的增加,T型梁的弯曲强度与模量均降低。当打印丝束间距为0.6~0.8 mm时,随着打印丝束间距的增加,T型梁的弯曲强度与模量降低。在T型梁从弯曲载荷加载初始到破坏失效阶段,对应特征信号可以聚类为五类,分别对应五种破坏模式,即基体开裂、层间剥离、纤维与基体脱粘、纤维开裂及纤维断裂,分类结果能够很好地解释弯曲破坏过程。

The continuous fiber reinforced resin 3D printing based on fused deposition technology offers a new rapid prototyping method for the fabrication of beam structures.It is also highly designable and enables the forming of lightweight and multifunctional beam structures.In this work,the flexural performance of T-beams with 0 mm and 5 mm rib heights at different printing parameters were tested.The flexural strengths and modulus of T-beams were investigated for print thicknesses of 0.7 mm,0.8 mm and 0.9 mm and print spacing of 0.6 mm,0.7 mm and 0.8 mm.At the same time,the acoustic emission technology was used to test and analyze the flexural failure process of the T-beam.The research utilized principal component analysis method and K-means++clustering algorithm to classify the collected signal damage.The results indicate that within the thickness of 0.7—0.9 mm,the flexural strength and modulus of the T-beam decrease with the increase of the thickness of the printing layer.Within the 0.6—0.8 mm spacing between the printing filaments,with the increase in the spacing between the printing filaments,the flexural strength and modulus of the T-beam also decrease correspondingly.From the initial loading of the T-beam to the failure stage of failure,the corresponding characteristic signals can be clustered into five categories.Corresponding to five failure modes,namely matrix cracking,interlayer debonding,fiber and resin debonding,fiber cracking and fiber fracture,the classification results can explain the failure process well.