Time-temperature behavior of carbon/epoxy laminates under creep loading

Heitor L Ornaghi,Roberta M Neves,Maria Odila H Cioffi,Francisco M Monticeli,José Humberto S Almeida

doi:10.1007/s11043-020-09463-z

Abstract

The time-temperature creep behavior of advanced composite laminates is herein determined through a comprehensive set of experiments and analytical modeling. A complete structure versus property relationship is determined through a wide range of temperature and applied stress levels at the three states of the composite: glassy, glass transition, and rubbery regions. Weibull, Eyring, Burger, and Findley models are employed to predict the experimental data and to better elucidate the material behavior. Experimental creep tests are carried out under ten min and two days aiming at calibrating fitting parameters, which are essential to validate short-term creep tests. The Weibull and Eyring models are more suitable for determining the time-temperature superposition (TTS) creep response in comparison to the Burger and Findley models.

Highlights

Creep in carbon fiber reinforced polymer (CFRP) composite materials may lead to unexpected stress redistribution over time, which can influence the durability and life service of composite structures (Gao et al 2018; Mohammad et al 2018; Wang et al 2019)
This paper aims at characterizing the creep behavior of carbon/epoxy composites using three different load levels at several temperature ranges
Four different models are employed to predict the creep response in the glassy, glass transition, and rubbery states: the Findley, Burger, Weibull, and Eyring models

Summary

Introduction

Creep in carbon fiber reinforced polymer (CFRP) composite materials may lead to unexpected stress redistribution over time, which can influence the durability and life service of composite structures (Gao et al 2018; Mohammad et al 2018; Wang et al 2019). Significant progress has been carried out in terms of the time-independent behavior of CFRP composites. In engineering applications, compliance and deformation properties are stress- and time-dependent (Almeida et al 2018a, 2018b; Ornaghi et al 2020). SP, Brazil 2 Department of Mechanical Engineering, Aalto University, 02150 Espoo, Finland 3 PPGE3M, Federal University of Rio Grande do Sul, Av. Bento Gonçalves 9500, Porto Alegre, RS, Brazil

Objectives

Results

Conclusion