Effect of thermal residual stress on the reflection spectrum from FBG sensors embedded in CFRP composites

2002 ◽  
Author(s):  
Yoji Okabe ◽  
Shigeki Yashiro ◽  
Ryohei Tsuji ◽  
Tadahito Mizutani ◽  
Nobuo Takeda
Keyword(s):  
Residual Stress ◽  
Reflection Spectrum ◽  
Thermal Residual Stress ◽  
Cfrp Composites ◽  
Fbg Sensors

Effect of Thermal Residual Stress on FBG Sensors Embedded in Composite T-Stiffened Panels

2012 ◽  
Vol 152-154 ◽  
pp. 1550-1554
Author(s):  
Yu Jing Zhou ◽  
Gang Liu ◽  
Xue Qin Li ◽  
Xiao Su Yi
Keyword(s):  
Residual Stress ◽  
Reflection Spectrum ◽  
Thermal Residual Stress ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Stiffened Panels ◽  
Stiffened Composite Panels ◽  
Fbg Sensors ◽  
Comparison Of The Results ◽  
Strain Responses

The reflection spectrum from the Fiber Bragg Grating (FBG) sensors embedded in the composite was disturbed because of the thermal residual stress. In this study, two types of the FBG sensors, uncoated and UV-cured resin coated FBG sensors, were embedded in the triangle area of the T-stiffened composite panels. The strains during the curing process were measured by these two kinds of FBG sensors. Through the comparison of the results, it was found that the effect of thermal residual stress on the reflection spectrum could be attenuated when the FBG sensor was coated with UV-cured resin. Furthermore, the strain responses during the low-velocity impact test were observed by both two FBG sensors. The maximum-strain measured by the coated FBG sensors was more accurately than that measured by the uncoated one.

Residual Stresses in Intrinsic UD-CFRP-Steel-Laminates - Experimental Determination, Identification of Sources, Effects and Modification Approaches

2015 ◽  
Vol 825-826 ◽  
pp. 369-376 ◽  
Author(s):  
Robert Prussak ◽  
Daniel Stefaniak ◽  
Christian Hühne ◽  
Michael Sinapius
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Tensile Strength ◽  
Epoxy Composite ◽  
Thermal Residual Stress ◽  
Fiber Metal Laminates ◽  
Fiber Metal ◽  
Impact Energies ◽  
The Impact ◽  
Specific Impact

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.

Micromechanical Modeling of Viscoplastic Behavior of Laminated Polymer Composites With Thermal Residual Stress Effect

2016 ◽  
Vol 138 (3) ◽  
Author(s):  
Qiang Chen ◽  
Xuefeng Chen ◽  
Zhi Zhai ◽  
Xiaojun Zhu ◽  
Zhibo Yang
Keyword(s):  
Residual Stress ◽  
Polymer Matrix Composites ◽  
Micromechanical Model ◽  
Thermal Residual Stress ◽  
Micromechanical Modeling ◽  
Multiscale Approach ◽  
Stress Effect ◽  
Accurate Analysis ◽  
Rate Dependent ◽  
Residual Stress Effect

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.

Thermal Residual Stress Simulation in Thermoplastic Filament Winding Process

2003 ◽  
Vol 16 (6) ◽  
pp. 497-519 ◽  
Author(s):  
Martin Schlottermuller ◽  
Haibo Lu ◽  
York Roth ◽  
Norbert Himmel ◽  
Ralf Schledjewski ◽  
...  
Keyword(s):  
Residual Stress ◽  
Filament Winding ◽  
Thermal Residual Stress ◽  
Filament Winding Process ◽  
Stress Simulation
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