The Mechanical Investigation of Filament-Wound CFRP Structures Subjected to Different Cooling Rates in Terms of Compressive Loading and Residual Stresses-An Experimental Approach.

Wojciech Błażejewski,Marek Lubecki,Michał Barcikowski,Paweł Stabla,Michał Stosiak,Grzegorz Lesiuk,Paweł Bury

doi:10.3390/ma14041041

Wojciech Błażejewski, Marek Lubecki + Show 5 more

Open Access

https://doi.org/10.3390/ma14041041

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Abstract

Although cooling at ambient temperature is widely used and is said to be safe and convenient, faster cooling may have an influence not only on the time of the manufacturing process but also on the mechanical response, especially the residual stress. The study aimed to investigate the influence of the cooling rate after curing on the mechanical response of filament-wound thick-walled carbon fiber reinforced polymer (CFRP) rings. Three cooling rates were taking into consideration: cooling with the oven, at room temperature, and in the water at 20 °C. The splitting method was used to examine the residual strains. In the radial compression test, the mechanical response was investigated between the rings with different cooling regimes. The FEM analysis of the compression test in elastic range was also performed. Both the splitting method and the radial compression test showed no significant difference in the mechanical response of the CFRP rings. The presented results showed that the fast-cooling rate slightly decreases the mechanical performance of the filament-wound rings.

Highlights

The manufacturing of composite structures is inherently linked to the mechanism of residual stress (RS) forming
This problem is strongly observed in the manufacturing of composite materials and their cylindrical structures commonly used in the oil and gas industry [7,8], the automotive sector including pressure vessels [9,10,11] as well as in the aerospace industry [12,13]
The set temperature in the oven was obtained after 15 min whereas the temperature of the composite ring rose significantly slower and obtained the set 80 ◦ C after about 3 h

Summary

Introduction

The manufacturing of composite structures is inherently linked to the mechanism of residual stress (RS) forming These stresses affect the mechanical properties of the manufactured composite structures, essentially, as evidenced in works [1,2,3,4,5,6]. It has been shown that the significant differences in temperature between the curing and cooling conditions resulted in direct thermal shock, and a considerable amount of residual stress was created. It resulted in the formation of significant amounts of residual stress, which may accelerate the destruction of the structure. Samples cooled at 25 ◦ C showed less residual stress than samples cooled at 0 ◦ C

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