scholarly journals Characteristics of Stress Wave Propagation of Carbon Fiber/Epoxy Laminates Fabricated by High-speed Automated Fiber Placement

Procedia CIRP ◽  
2016 ◽  
Vol 56 ◽  
pp. 255-260 ◽  
Author(s):  
Shouzheng Sun ◽  
Zhenyu Han ◽  
Hongya Fu
2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Zhenyu Han ◽  
Shouzheng Sun ◽  
Zhongxi Shao ◽  
Hongya Fu

Processing optimization is an important means to inhibit manufacturing defects efficiently. However, processing optimization used by experiments or macroscopic theories in high-speed automated fiber placement (AFP) suffers from some restrictions, because multiscale effect of laying tows and their manufacturing defects could not be considered. In this paper, processing parameters, including compaction force, laying speed, and preheating temperature, are optimized by multiscale collaborative optimization in AFP process. Firstly, rational model between cracks and strain energy is revealed in order that the formative possibility of cracks could be assessed by using strain energy or its density. Following that, an antisequential hierarchical multiscale collaborative optimization method is presented to resolve multiscale effect of structure and mechanical properties for laying tows or cracks in high-speed automated fiber placement process. According to the above method and taking carbon fiber/epoxy tow as an example, multiscale mechanical properties of laying tow under different processing parameters are investigated through simulation, which includes recoverable strain energy (ALLSE) of macroscale, strain energy density (SED) of mesoscale, and interface absorbability and matrix fluidity of microscale. Finally, response surface method (RSM) is used to optimize the processing parameters. Two groups of processing parameters, which have higher desirability, are obtained to achieve the purpose of multiscale collaborative optimization.


1984 ◽  
Vol 51 (2) ◽  
pp. 345-353 ◽  
Author(s):  
K. R. Y. Simha ◽  
W. L. Fourney

A general formulation is presented for the analysis of stress wave propagation through the junction of rectangular bars. The analysis is applied to the case of two bars meeting at right angles and is used to theoretically predict the passage of longitudinal waves through the junction. An experimental investigation of the phenomenon, using dynamic photoelasticity is conducted with a high-speed multiple spark gap camera of the Cranz-Schardin type. Three different geometries are tested to represent the most common types of junctions encountered in practice. In each of the cases, experimentally obtained results are observed to be very consistent with the theoretical predictions.


2014 ◽  
Vol 590 ◽  
pp. 63-68 ◽  
Author(s):  
Zhu Hua Tan ◽  
Bo Zhang ◽  
Peng Cheng Zhai

The effect of stress wave propagation on dynamic response of square tube was investigated by the experimental and numerical simulation methods in the present paper. The square tubes were subjected to the axial impact by split Hopkinson pressure bar. And the deformation process of each square tube was recorded by a high speed camera. Typical dynamic plastic buckling phenomena were observed in the experiments. And the numerical calculation of the experimental load case was conducted to analyze the effect of the stress wave propagation on the initial buckling of the square tube. The results show that there is obvious stress wave propagation in the square tube before the buckling of the square tube. And the initial buckling starts from the rear end of the tube due to the propagation of the stress wave. The relation between the stress wave propagation and initial buckling of the square tube was also discussed.


2010 ◽  
Vol 70 (12) ◽  
pp. 1669-1673 ◽  
Author(s):  
Yangwei Wang ◽  
Fuchi Wang ◽  
Xiaodong Yu ◽  
Zhuang Ma ◽  
Jubin Gao ◽  
...  

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