Carbon Fiber-reinforced Epoxy Research Articles

Compact-tension-shear specimen for orthotropic materials in fracture toughness testing

Conducting Compact-Tension-Shear (CTS) tests emerges as a promising research methodology to determine the fracture toughness of orthotropic materials in mixed-mode I&II. However, the absence of pertinent fracture parameter solutions incorporating material orthotropy impedes the further application and standardization of CTS testing. Therefore, this study performed a systematic two-dimensional finite element analysis on orthotropic CTS specimens to evaluate critical fracture parameters, including the normalized stress intensity factors (YI, YII) and compliance (u). First, the impacts of three commonly cited boundary conditions (BCs) of CTS models were investigated, revealing that the simplified or equivalent methods developed for isotropic CTS models are no longer applicable. Subsequently, the suitable CTS models were used to analysis the coupling effects of material orthotropy (λ, ρ), crack length ratios (a/W), and loading angles (β). Findings indicated that YI or u no longer exhibit a monotonic relationship with respect to a/W or β under strong orthotropy. The impact of λ and ρ on fracture parameters is equally significant across different geometries and loading conditions. Further, the impact of YII under orthotropy is relatively small, while the more affected YI may have a difference compared to isotropic results of over 80%. Finally, CTS tests were carried out on the unidirectional carbon fiber-reinforced epoxy resin composite measuring the fracture toughness in mixed-modes I&II. The obtained fracture parameter solutions were applied and validated during the process. The acquired results are poised to contribute to the advancement of fracture toughness testing standardization for orthotropic materials under mixed-mode loading.

Panoramic View of Interface-Related Thermo-oxidative Aging of Carbon Fiber-Reinforced Epoxy Composites

Panoramic View of Interface-Related Thermo-oxidative Aging of Carbon Fiber-Reinforced Epoxy Composites

Determination of the In-Plane Shear Behavior of and Process Influence on Uncured Unidirectional CF/Epoxy Prepreg Using Digital Image Correlation Analysis

The investigation of the in-plane shear behavior of prepreg is crucial for understanding the generation of wrinkles of preforms in advanced composite manufacturing processes, such as automated fiber placement and thermoforming. Despite this significance, there is currently no standardized test method for characterizing uncured unidirectional (UD) prepreg. This paper introduces a ±45° off-axis tensile test designed to assess the in-plane shear behavior of UD carbon fiber-reinforced epoxy prepreg (CF/epoxy). Digital image correlation (DIC) was employed to quantitatively track the strains in three dimensions and the shear angle evolution during the stretching process. The influences of the temperature and stretching rate on the in-plane shear behavior of the prepreg were further investigated. The results reveal that four shear characteristic zones and wrinkling behaviors are clearly distinguished. The actual in-plane shear angle is significantly lower than the theoretical value due to fiber constraints from both the in-plane and out-of-plane aspects. When the off-axis tensile displacement (d) is less than 15.6 mm, the ±45° specimens primarily exhibit macroscale in-plane shear behavior, induced by interlaminar interface shear between the +45° ply and −45° ply at the mesoscale. The shear angle increases linearly with the d. However, when d > 15.6 mm, fiber squeezing and wrinkling begin to occur. When d > 29 mm, the in-plane shear disappears in the completely sheared zone (A). The reduction in the resin viscosity of the CF/epoxy prepreg caused by increased temperature is identified as the primary factor in lowering the in-plane shear force resistance, followed by the effect of the increasing resin curing degree. Higher shear rates can lead to a substantial increase in shear forces, eventually causing cracking failure in the prepreg. The findings demonstrate the feasibility of the test method for predicting and extracting uncured prepreg in-plane shear behaviors and the strain-rate and temperature dependency of the material response.

Investigation of fracture behavior and mechanical properties of epoxy composites supported with MWCNTs microscopically

Adding of a multi-walled carbon nanotubes (MWCNTs) to epoxy resin has shown promising results in improving fracture toughness in bulk epoxy and carbon fiber-reinforced epoxy composites (CFRP). using a hand layup proceeding followed by the so called vacuum bagging process method, carbon fiber-reinforced polymer multi-wall carbon nanotubes (MWCNTs) was added to an epoxy resin with a weight percentage mixing of 1% wt., 1.25% wt., and 1.5 % wt. MWCNTs. Furthermore, the specimen underwent analysis via Fourier-Transform Infrared (FTIR) spectroscopy, and X-ray Diffraction (XRD) spectroscopy, the composites were subjected to a microscopic examination using a Scanning Electron Microscope (SEM). FTIR and XRD verified the folding and unfolding of the polymer, in addition, the mechanical properties including tensile strength, bending stress, and impact behavior were investigated as well as the hardness test. The obtained results showed a significant improvement of about (40 %) in tensile strength, (53 %) in bending stress at 1 % wt. MWCNTs, and (70 %) percentage increment in the strength of Impact at 1.25 % wt. MWCNTs. And the gained hardness was about 40.5 HV which were compared with a reference substance named Carbon Fiber (CF) without any addition of nano materials. Carbon nanotubes have demonstrated their potential to enhance the mechanical properties of fiber-reinforced polymers, so this investigative study employs comprehensive characterization techniques, and demonstrates significant improvements in mechanical properties for the modified polymeric composite materials supported with nano materials.

Comparison of pin-loaded tensile behavior and failure behavior of thermosetting and thermoplastic composite

This study investigated the pin-loaded tensile behavior, bearing strength, and failure mechanisms of thermosetting and thermoplastic composite materials. Specifically, the investigation focuses on carbon-fiber-reinforced polyetherketoneketone (CF/PEKK) and carbon-fiber-reinforced epoxy (CF/EPOXY). Notably, CF/PEKK exhibited a shear-out failure mode, surpassing CF/EPOXY with a 56.4% higher peak load. The absence of crack propagation in CF/EPOXY, attributed to the presence of yarn at a 90∘ angle, leads to bearing failure. In contrast, CF/PEKK demonstrates a significantly higher bearing strength, approximately 150[Formula: see text]MPa greater than CF/EPOXY. This discrepancy in performance suggests that CF/PEKK holds promise as a structural material for applications involving the fastening of thermoplastic composites, presenting a viable alternative to traditional thermosetting composites. The findings imply that the unique failure mechanisms and enhanced mechanical properties of CF/PEKK make it a compelling candidate for use in scenarios where thermosetting composites are conventionally applied. This study contributes valuable insights into the potential advancements and applications of thermoplastic composites in structural materials, paving the way for optimized and innovative engineering solutions.

Micromechanical modeling for longitudinal tensile property of unidirectional CFRP considering dispersion of fiber properties

Longitudinal tensile failure prediction has always been the focus of research on unidirectional (UD) Carbon Fiber Reinforced Polymer (CFRP). In this paper, the longitudinal tensile tests of unidirectional T800 grade carbon fiber reinforced epoxy resin composite were carried out first. The experimental stress–strain curves show that there are obvious progressive damages before the final failures of the specimens. However, this phenomenon is usually neglected in most of the existing investigations and tests to only obtain elastic modulus and ultimate strength. Thus, a Representative Volume Element (RVE) model based on micromechanics was established using finite element method, considering the randomness of fiber spatial distribution and fiber strength. The tensile strength of fiber monofilaments was assumed to follow a statistical two-parameter Weibull distribution. The failure process of UD composite under longitudinal tensile load was simulated by explicit finite element method. The stress–strain curves obtained by simulation are in good agreement with the experimental results. Finally, the influence of different boundary conditions on the calculation of the RVE was studied. It is found that the final failure strengths of the RVE with uniform displacement boundary conditions are similar to the case of periodic boundary conditions, while the former has higher computational efficiency.

Experimental and numerical study of the effects of fiber orientation on stress concentration of CFRE

Carbon fiber reinforced composites are broadly employed, as structural members, in many industrial applications especially in the avionic industry due to their high strength-to-weight ratio. Circular holes are commonly used in these members for fastening, bearing, reducing weight, and others. Therefore, several experimental and analytical studies were introduced to figure out the stress concentration behavior around the vicinity of the holes under different loading conditions. However, no reports are delivered to study the effect of fiber orientation on the stress concentration factor of unidirectional carbon fiber reinforced epoxy (CFRE) composites with a hole under tension. Thus, the current work is targeted to understand the relationship between stress concentration factor (SCF) and fiber orientation in CFRE orthotropic plates. The unnotched and notched composite samples, with four different fiber orientations, were experimentally investigated in a tension test. The SCF of samples was calculated using analytical and computational FE methods. The failure criterion of open-hole tensile (OHT) test samples was also analyzed. The experimental results demonstrated that there is no significant effect of fiber orientation on the normalized strength. Yet based on the stiffness matrix of isotropic materials, a pronounced effect of the fiber orientation on the SCF is detected when using analytical calculations. The present research arises the need for further investigations to find a correlation between experimental and analytical results of SCF in unidirectional CFRE with a central hole at different fiber orientations.

Multiscale analysis method and experiments for the transverse mechanical property of unidirectional fiber-reinforced composites

Carbon fiber-reinforced epoxy matrix composite laminates have been widely used in the case of advanced aero-engines, due to their high specific mechanical properties and mature production technology. In order to predict accurately the transverse mechanical properties of composites, this paper developed a multiscale analysis method which consists of three scales: At the microscale, an interfacial cohesive zone model is established based on atomic potential energy to describe the interface. At the mesoscale, a unit cell model is established to represent the fiber, matrix, and interface. At the macroscale, the homogenization method, failure criteria, and damage degradation models are utilized to predict transverse mechanical properties. The results of predictions are compared with experimental tests, and it is found that the maximum errors are less than 3%. Furthermore, the predicted damage evolution path aligns with the experimental results, thus validating the accuracy of the multiscale analysis method. By employing the multiscale analysis method, the effects of interfacial strength on the macroscopic transverse mechanical properties are analyzed. The simulation results indicate that: The interfacial strength has a more pronounced influence on the transverse strength and ultimate strain compared with the transverse modulus. Reducing the interfacial strength has a greater influence on the transverse modulus, strength, and ultimate strain than increasing the interfacial strength. The interfacial cohesive zone model can reflect the nonlinearity of epoxy matrix composite materials. Overall, the multiscale analysis method proves to be effective in accurately predicting the transverse mechanical properties of composites, and provides insights into the interfacial strength’s role in these properties.

Effect of carbon nanotubes on thermoset curing and mechanical properties of carbon fiber reinforced epoxy resin laminates fabricated by self‐resistance electric heating

AbstractSelf‐resistance electric (SRE) heating for the curing of carbon fiber reinforced plastic (CFRP) offers the benefits of saving energy consumption and reducing investment in equipment. In this work, the investigation was carried out to illustrate the effect of carbon nanotubes (CNTs) addition (0.5, 1.0, and 1.5 wt%) on the thermoset curing and mechanical properties of carbon fiber‐reinforced epoxy laminates fabricated by SRE heating method. The results show that adding CNTs can improve the temperature uniformity and interlayer‐resin flow during the SRE heating process and have a limited influence on the curing degree of CFRP composites. The tensile strength in the longitudinal direction of the composites increased with the increase of CNT addition. Meanwhile, the flexural strength and interlaminar shear strength had the maximum value with the CNTs content of 0.5 wt% and decreased significantly at the CNTs content of 1.5 wt%. It concludes that the appropriate content of CNTs addition has the potential to improve the thermoset curing performance and mechanical properties of the CFRP laminate composites fabricated by SRE heating.Highlights This study focuses on the effect of CNT addition on SRE heating for CFRP. The addition of CNTs improved the temperature uniformity during SRE heating. The addition of CNTs can reduce the voids of SRE‐cured CFRP composites. Threshold value of CNTs affected the mechanical performance of SRE‐cured CFRP.

Modal and stress behavioral for CFRP composite lifting lug

Purpose In the present study, a steel lifting lug is replaced with a composite (carbon fiber-reinforced epoxy [CFRP]) lifting lug made of a carbon/epoxy composite. The purpose of this paper was to obtain a composite lifting lug with a higher level of strength that is capable of carrying loads without failure. Design/methodology/approach The vibration and static behaviors of steel and composite lifting lugs have been investigated using finite element analysis (FEA), ANSYS software. The main consideration in the design of the composite (CFRP) lifting lug was that the displacement of both steel and composite lugs was the same under the same load. Hence, by using the FEA displacement result of the steel lifting lug, the thickness of the composite lifting lug is determined using FEA. Findings Compared to the steel lifting lug, the composite (CFRP) lifting lug has much lower stresses and much higher natural frequencies. Static behavior was experienced by the composite lifting lug, showing a reduction in von Mises stress, third principal stress and XZ shear stress, respectively, by 48.4%, 34.6% and 89.8%, respectively, when compared with the steel lifting lug. A higher natural frequency of mode shape swaying in X (258.976√1,000 Hz) was experienced by the composite lifting lug when compared to the steel lifting lug (195.935√1,000 Hz). The safe strength of the design composite lifting lug has been proven by FEA results, which showed that the composite (CFRP) lifting lug has a higher factor of safety in all developed stresses than the steel lifting lug. According to von Mises stress, the factor of safety of the composite lifting lug is increased by 76% when compared to the steel lifting lug. The von Mises stress at the edge of the hole in the composite lifting lug is reduced from 23.763 MPa to 20.775 MPa when compared to the steel lifting lug. Originality/value This work presents the designed composite (CFRP) lifting lug, which will be able to carry loads with more safety than a steel one.

Design and study of biomimetic resin matrix composites based on shellfish structure

Differences in microstructure can often lead to large differences in mechanical properties. Here, the composition, microstructure, and mechanical properties of mussel, scallop, and ostreidae were researched. And subsequently, three bionic models were designed based on the microstructures of the three shellfish. Three models were prepared by printing the substrate with light-cured resin and filling with carbon fiber reinforced epoxy resin. The mechanical properties and reinforcement mechanisms of the three models were also investigated. The bending fracture force, compression fracture, and the impact fracture energy of mussels was best of three shellfish. The bionic model 1 with mimic mussel structure has good mechanical properties. Bending strength of model 1 is 42.80 ± 7.00 MPa which was 5.42% higher than bionic model 2 and bionic model 3, and 33.75% higher than that of the pure epoxy resin (32.00 MPa). The absorbed energy of the model 1 is 63.53 ± 2.56%, which is 3.82% and 7.89% higher than model 2 and model 3, respectively. The fracture showed obvious toughness fracture. The unique crack deflection induced by the structure also leads to enhanced mechanical properties. This study provides new design ideas and references for the structural design of high-strength composites.

Mechanical properties of a carbon fiber reinforced epoxy resin composite improved by integrating multi-walled carbon nanotubes and graphene nanoplatelets

The pairs of nanofillers prepared by graphene nanoplatelets (GNPs) and multi-walled carbon nanotubes (MWCNTs) were added to the epoxy matrix in various ratios to produce hybrid epoxy nanocomposites. The effects of the presence of these nanofillers at 0.1–0.4 wt.% on the mechanical and thermal properties were tested. Likewise, carbon fiber reinforced MWCNT/GNP modified epoxy nanocomposite laminates were also manufactured and tested. The dispersion of nanofiller in the polymer matrix was evaluated by Scanning Electron Microscopy (SEM). It was determined that the hybrid composite consisting of a MWCNT:GNP ratio of 1:3 and a nanofiller ratio of 0.3 wt.% showed the best mechanical properties with a tensile strength of 75.1 MPa. The presence of GNPs and MWCNT nanofillers in epoxy/carbon fiber laminates influenced positively the tensile strength and strain but negatively the elastic modulus. Glass transition temperature of epoxy increased from 87.25°C to 114.67°C for MWCNT:GNP ratio of 1:1 (0.3 wt.%).

Chemical recovery of carbon fibers from composites via plasma assisted solvolysis

In this work plasma assisted solvolysis using nitric acid is proposed for chemical recovery of carbon fibers from carbon fiber-reinforced epoxy resin composites (CFRCs). Complete decomposition of the epoxy matrix could be achieved, regardless the composites’ geometry. The efficiency of the process was examined in terms of a) process duration, b) resin decomposition rate and c) materials properties. SEM and EDX data showed that the recovered fiber surfaces are almost free of epoxy resin residuals and their tensile strength was comparable to that of typical virgin carbon fiber. The process decomposition efficiency is very high without requiring additional organic solvents or high temperature / pressure, stressing the potential of this method for viable recycling of CFRCs.

Convolutional neural network and level-set spectral element method for ultrasonic imaging of delamination cavities in an anisotropic composite structure

We present a computational approach that incorporates a convolutional neural network (CNN) for detecting internal delamination in a layered 2D plane-strain anisotropic composite structure of transient elastodynamic fields. The two-dimensional spectral element method (SEM) is utilized to simulate the propagation of elastic waves in an orthotropic solid sandwiched by isotropic solids and their interaction with the internal delamination cavity. This work generates training data consisting of input-layer features (i.e., measured wave signals) and output-layer features (i.e., element types, such as void or regular, of all elements in a domain).To accelerate training data generation, we utilize explicit time integration (e.g., the Runge–Kutta scheme) coupled with an SEM wave solver. Applying the level-set method additionally avoids having to perform an expensive re-meshing process for every possible configuration of the delamination cavities during the data-generation phase. The CNN is trained to classify each element as a non-void or void element from the measured wave signals. Clusters of identified void elements reconstruct targeted cavities. Once our neural network is trained using synthetic data, we analyze how effectively the CNN performs on synthetic measurement data. To this end, we use blind test data from a third-party simulator that explicitly models the traction-free boundary of cavities for anisotropic materials without the application of the level-set method.Our numerical examples show that our approach can effectively detect the internal cavities in an anisotropic structure made of aluminum and carbon fiber-reinforced epoxy using the measured elastic waves without any prior information about the cavities’ locations, shapes, and numbers. The presented method can be extended into a more realistic 3D setting and utilized for the nondestructive test of various anisotropic composite structures.

Investigation of the influence of Halloysite Nanotubes (HNTs) on the low-velocity impact behavior of carbon fiber-reinforced epoxy composites

This study explores the impact of incorporating Halloysite Nanotubes (HNTs) nanoparticles on the low-velocity impact (LVI) behavior of carbon fiber (CF) laminate epoxy nanocomposites. The objective of this investigation was to observe the effects of different nanotube loadings (0.5[Formula: see text]wt.% and 0.7[Formula: see text]wt.%) on CF composites and assess their impact resistance. To achieve this, the CF was subjected to Electrophoretic Deposition (EPD) process to introduce the HNTs. Vacuum-assisted Resin Transfer Molding (VaRTM) was employed to fabricate the CF-reinforced epoxy-based laminated nanocomposites with incorporated HNTs. LVI tests were conducted following the ASTM-D-7136 standard, utilizing impact energies of 10[Formula: see text]J and 15[Formula: see text]J. Subsequently, the damaged areas within the composites were examined using optical microscopy (OM) and scanning electron microscope (SEM). The findings of this investigation revealed a significant enhancement in impact damage resistance with the addition of HNTs. The highest damage resistance and minimal energy absorption were observed at a loading of 0.7[Formula: see text]wt.% HNTs. The results reveal that incorporating 0.7[Formula: see text]wt.% HNTs substantially reduces delamination damage, influenced by absorbed impact energy. As well it composite underscores enhanced interlaminar bonding through 0.5[Formula: see text]wt.% and 0.7[Formula: see text]wt.% HNTs modification. Hence, we confidently assert that the addition of HNTs nanoparticles to CF/epoxy composites has considerably influenced the impact response of the nanocomposites.

Efficient degradation of amine cured epoxy resin via the cleavage of C-N bond by amphiphilic dodecylbenzenesulfonic acid

Amine-cured epoxy resin (EP) is often compounded with carbon fiber (CF) used for wind power blades due to its excellent performance. However, the insolubility and infusibility of service-life-expired carbon fiber reinforced epoxy resin (CFREP) hinder its sustainable recycling. We reported a new strategy for efficient degradation of EP and CFREP with 0.5 mol% amphiphilic dodecylbenzenesulfonic acid (DBSA) in aqueous system. It was found that the strong lipophilicity of DBSA accelerated its enrichment on EP surface, and further promoted the diffusion of DBSA and H2O to the resin bulk phase. As a result, the degradation ratio of the EP powder reached 100 % at 190 °C only in 10 h. The characterization of FT-IR and NMR proved that the degradation mechanism of EP was the selective cleavage of C-N bond catalyzed by H+. The resin degradation products (RDP) containing active hydrogen were used to prepare polyurethane (PU) with good mechanical properties. This method achieves complete recycling of waste CFREP in aqueous systems.

POSS-polyurethane prepolymer strengthened and toughened CF/epoxy resin composites for room and simulated Arctic ambient temperature

As an important material candidate for automotive, aviation, and aerospace, the wide application of carbon fiber-reinforced epoxy resin composites (CFRPs) was important. However, restricted by the low toughness. Herein, octaaminopropyl cage polysilsesquioxane-polyurethane prepolymer (POSS-PU) was synthesized by in-situ polymerization of PU on the POSS, and then employed as the modifier for epoxy resin (EP). Compared to pristine EP, the toughness of the 7.5 wt% POSS0.5-PU/EP was increased by 115.3 % without compromising the tensile strength and Tg. The unnotched impact strength, interlaminar shear strength (ILSS), and flexural strength of the CFRPs prepared from the modified EP were increased by 73.5 %, 7.5 %, and 42.4 %, compared to CF/EP. Additionally, the mechanical properties of CFRPs maintained a substantial improvement under low-temperature, and the CF/7.5 wt% POSS0.5-PU/EP was increased by 72.9 % (impact strength) and 21.7 % (ILSS), compared to those of CF/EP. Compared to the improvement in the toughness of CFRPs at room temperature, the retention rate of toughness enhancement at low temperature was approximately 100 %. CFRPs prepared by POSSx-PU/EP offered outstanding mechanical properties and hence showed great potential for future industrial applications.

GO-tagged PEI sizing agent imparts self-healing and excellent mechanical properties to carbon fiber reinforced epoxy laminates.

Carbon fiber-reinforced epoxy (CFRE) laminates have attracted significant attention as a structural material specifically in the aerospace industry. In recent times, various strategies have been developed to modify the carbon fiber (CF) surface as the interface between the epoxy matrix and CFs plays a pivotal role in determining the overall performance of CFRE laminates. In the present work, graphene oxide (GO) was used to tag a polyetherimide (PEI, termed BA) containing exchangeable bonds and was employed as a sizing agent to improve the interfacial adhesion between CFs and epoxy. This unique GO-tagged-BA sizing agent termed BAGO significantly enhanced the mechanical properties of CFRE laminates by promoting stronger interactions between CFs and the epoxy matrix. The successful synthesis of BAGO was verified by Fourier-transform infrared spectroscopy. Additionally, the partial reduction of GO owing to this tagging with BA was further confirmed by X-ray diffraction and Raman spectroscopy, and the thermal stability of this unique sizing agent was evaluated using thermogravimetric analysis. The amount of GO in BAGO was optimized as 0.25 wt% of BA termed 0.25-BAGO. The 0.25-BAGO sizing agent resulted in a significant increase in surface roughness, from 15 nm to 140 nm, and surface energy, from 13.2 to 34.7 mN m-1 of CF. The laminates prepared from 0.25-BAGO exhibited a remarkable 40% increase in flexural strength (FS) and a 35% increase in interlaminar shear strength (ILSS) due to interfacial strengthening between epoxy and CFs. In addition, these laminates exhibited a self-healing efficiency of 51% in ILSS due to the presence of dynamic disulfide bonds in BAGO. Interestingly, the laminates with 0.25-BAGO exhibited enhanced Joule heating and enhanced deicing, though the EMI shielding efficiency slightly declined.

A facile and efficient solvothermal degradation route for carbon fiber reinforced epoxy resin composite waste

Carbon fiber reinforced epoxy resin composite (CF/EP) is widely used in aerospace applications, automotive industry, construction engineering and many other important sectors, for it has excellent mechanical properties and corrosion resistance. However, the three-dimensional cross-linked structure of the cured epoxy resin determines its insolubility and non-melting characteristics, which makes it challenging to efficiently degrade CF/EP waste and recycle the high-value carbon fibers. In this study we propose a strategy that degrades the CF/EP waste via a facile and efficient solvothermal degradation route. The results showed that the degradation ratio of the resin increased significantly with the rise in reaction temperature. When the reaction temperature reached 180 °C there were no obvious resin residues on the surface of the recycled carbon fibers. It was found that the recycled carbon fibers were not obviously damaged during the solvothermal degradation process, as shown by the scanning electron microscopy (SEM), X-ray diffraction (XRD) and Raman analyses.

Continuum Mechanics Models for Describing the Creep and Physical Aging Behaviors of Laminated Composites

Two types of carbon fiber-reinforced epoxy composite laminates are chosen for long-term tensile creep tests under different temperatures and load levels. Their time-dependent and non-monotonic deformations indicate clearly both temperature effect and physical aging effect. To characterize these viscoelastic behavior, two phenomenological constitutive models and one physical model are developed. The linear viscoelastic model based on the Boltzmann superposition principle is able to describe reasonably the deformations at relatively lower stress levels and temperatures. The nonlinear viscoelastic model of Schapery’s single-integral form, together with a usage of effective time theory, could describe nicely all the effects of temperature, stress, and physical aging. The physical model based on Ngai’s coupling mechanism concept is further combined with the framework of Schapery’s nonlinear viscoelastic theory, which may provide certain physical understanding about the effect of aging behavior on long-term creep deformation of the laminated composites. Numerical modelling by finite element method are implemented, and comparisons between the experimental and simulation results are demonstrated.