A methodology for predicting processing induced thermal residual stress in thermoplastic composite at the microscale

Author(s):  
Nithin K. Parambil ◽  
Branndon R. Chen ◽  
Joseph M. Deitzel ◽  
John W. Gillespie
2015 ◽  
Vol 825-826 ◽  
pp. 369-376 ◽  
Author(s):  
Robert Prussak ◽  
Daniel Stefaniak ◽  
Christian Hühne ◽  
Michael Sinapius

This paper focuses on the reduction of process-related thermal residual stress in fiber metal laminates and its impact on the mechanical properties. Different modifications during fabrication of co-cure bonded steel/carbon epoxy composite hybrid structures were investigated. Specific examinations are conducted on UD-CFRP-Steel specimens, modifying temperature, pressure or using a thermal expansion clamp during manufacturing. The impact of these parameters is then measured on the deflection of asymmetrical specimens or due yield-strength measurements of symmetrical specimens. The tensile strength is recorded to investigate the effect of thermal residual stress on the mechanical properties. Impact tests are performed to determine the influence on resulting damage areas at specific impact energies. The experiments revealed that the investigated modifications during processing of UD-CFRP-Steel specimens can significantly lower the thermal residual stress and thereby improve the tensile strength.


2002 ◽  
Author(s):  
Yoji Okabe ◽  
Shigeki Yashiro ◽  
Ryohei Tsuji ◽  
Tadahito Mizutani ◽  
Nobuo Takeda

Author(s):  
Qiang Chen ◽  
Xuefeng Chen ◽  
Zhi Zhai ◽  
Xiaojun Zhu ◽  
Zhibo Yang

In this paper, a multiscale approach has been developed for investigating the rate-dependent viscoplastic behavior of polymer matrix composites (PMCs) with thermal residual stress effect. The finite-volume direct averaging micromechanics (FVDAM), which effectively predicts nonlinear response of unidirectional fiber reinforced composites, is incorporated with improved Bodner–Partom model to describe the viscoplastic behavior of PMCs. The new micromechanical model is then implemented into the classical laminate theory, enabling efficient and accurate analysis of multidirectional PMCs. The proposed multiscale theory not only predicts effective thermomechanical viscoplastic response of PMCs but also provides local fluctuations of fields within composite microstructures. The deformation behaviors of several unidirectional and multidirectional PMCs with various fiber configurations are extensively simulated at different strain rates, which show a good agreement with the experimental data found from the literature. Influence of thermal residual stress on the viscoplastic behavior of PMCs is closely related to fiber orientation. In addition, the thermal residual stress effect cannot be neglected in order to accurately describe the rate-dependent viscoplastic behavior of PMCs.


Author(s):  
Weihao Chai ◽  
Xiandong Liu ◽  
Yinchun Shan ◽  
Xiaofei Wan ◽  
Er Jiang

To increase the simulation accuracy, a finite element analysis method for the prediction of the residual stress distribution in the injection molded wheel made of the long glass fiber-reinforced thermoplastic composite (LGFT) is studied, and a simulation method of the wheel bending fatigue test considering the residual stress distribution is investigated in this paper. First, the in-cavity residual stress is calculated using the molding simulation method. Then the residual stress relaxation process is analyzed and the final residual stress distribution is obtained. With the residual stress as the initial stress, the structural simulation of the LGFT wheel under the bending load is performed. To evaluate the influence of the residual stress on the LGFT wheel, an additional simulation without considering the residual stress is conducted. The result shows that the interior stress considering residual stress is much higher than that without considering residual stress. To verify the simulation accuracy of these two cases, the high-stress area locations in the simulation results are compared with the damage locations in physical bending fatigue test. The result illustrates that the simulation result considering the residual stress accords with the experimental result better. Therefore, the simulation result of the residual stress is reasonable, and it is necessary to consider residual stress in the simulation of the LGFT wheel.


2003 ◽  
Vol 16 (6) ◽  
pp. 497-519 ◽  
Author(s):  
Martin Schlottermuller ◽  
Haibo Lu ◽  
York Roth ◽  
Norbert Himmel ◽  
Ralf Schledjewski ◽  
...  

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