Aspect of fatigue analysis of composite materials: a review

This paper reviewed the aspect of fatigue approaches and analysis in a fibre reinforced composite materials which have been done by researchers worldwide. The aim of this review is to provide a better picture on analytical approaches that are presently available for predicting fatigue life in composite materials. This review also proposes a new interpretation of available theories and identifies area in fatigue of natural fibre reinforced composite materials. Thus, it was concluded there are still very limited studies on fatigue analysis of natural fibre reinforced composite materials, especially using non-destructive technique (NDT) methods and a new mathematical modelling on fatigue should be formulated

Fatigue life estimation of kenaf reinforced composite materials by non-destructive techniques

In this study, fatigue life of natural fiber reinforced composite materials was predicted due to manufacturing defects fatigue damage modes. Kenaf bast fibers were used to fabricate natural fiber composite materials with epoxy as a binding material. The Kenaf fiber reinforced composites were manufactured using a hand lay-up process. The defects in Kenaf reinforced composite materials were determined by a non-destructive technique using Infrared (IR) thermal imager. The thermography analyses were verified by optical microscope and scanning electron microscope (SEM) investigations. Then, the Mathematical model for estimating fatigue life by IR thermal imaging technique based on damage accumulation model is proposed. This proposed model is named as S-IR thermal imaging fatigue life model. Determinations of fatigue damage has been predicted and it found that it damage has been fixed with the predicting results. S-IR model proposed that 60% kenaf epoxy with thickness 0.3 cm is recommended as the best formulation to fabricate the specimens due to a longer fatigue life recorded and the result obtained from the fatigue cyclic tension test shows that 60% kenaf epoxy with thickness 0.3 cm had the highest fatigue resistance as indicated by a highest range of stress level, 119.71-53.20 MPa

Fatigue life estimation of kenaf reinforced composite materials by non-destructive techniques

In this study, fatigue life of natural fiber reinforced composite materials was predicted due to manufacturing defects fatigue damage modes. Kenaf bast fibers were used to fabricate natural fiber composite materials with epoxy as a binding material. The Kenaf fiber reinforced composites were manufactured using a hand lay-up process. The defects in Kenaf reinforced composite materials were determined by a non-destructive technique using Infrared (IR) thermal imager. The thermography analyses were verified by optical microscope and scanning electron microscope (SEM) investigations. Then, the Mathematical model for estimating fatigue life by IR thermal imaging technique based on damage accumulation model is proposed. This proposed model is named as S-IR thermal imaging fatigue life model. Determinations of fatigue damage has been predicted and it found that it damage has been fixed with the predicting results. S-IR model proposed that 60% kenaf epoxy with thickness 0.3 cm is recommended as the best formulation to fabricate the specimens due to a longer fatigue life recorded and the result obtained from the fatigue cyclic tension test shows that 60% kenaf epoxy with thickness 0.3 cm had the highest fatigue resistance as indicated by a highest range of stress level, 119.71-53.20 MPa

Detection of defects in natural composite materials using a thermal imaging technique

Nowadays, non-destructive testing (NDT) is frequently replacing destructive techniques in determining the properties of materials. In this study, defects in Kenaf/epoxy composite materials were detected using an inyyfrared (IR) thermal imaging technique, which is one of the most practical non-destructive techniques currently applied. Kenaf bast fibres were used to fabricate composite materials with epoxy resin as a binding material. The composites were manufactured using a manual lay-up process. The thermography analysis of the IR camera were verified by optical microscope and scanning electron microscope (SEM) investigations. The defect detection accuracy of this technology is 95%

Determination of defects and damage modes in kenaf-reinforced epoxy composites under fatigue loading using thermal imaging and SEM techniques

In engineering design, concerns arose on the fatigue behaviours of composite materials.Much effort has been done to estimate the fatigue life by which destructive techniques were commonly used. Recently, non-destructive techniques (NDT) are increasingly being used on composite materials to detect defects. Parallel to the development, shifting interests from traditional monolithic materials to fiber reinforced polymer based materials have been demonstrated by researchers and engineers. Nevertheless, information on the use of NDT on natural fiber reinforced composite materials is still sparse. The present study was set out to detect defects and estimate fatigue life in natural fiber reinforced composite materials. In making the composite, kenaf bast was used as a reinforcement fiber with epoxy as the matrix. The NDT employed to serve the study purposes are Infrared (IR) thermal imaging and optical microscope. In parallel,destructive technique (DT) was also used in this study specifically in carrying out the fatigue tension-tension test and scanning electron microscope (SEM). By and large, the DT was used just to verify all the results by NDT. The advantages of using NDT via IR thermal imaging in kenaf reinforced epoxy composites to estimate the fatigue life are evidenced in the following results: IR has successfully detected five types of manufacturing defects in kenaf reinforced epoxy composites due to manufacturing process. The defects are voids, resin rich area, pockets of undispersed cross-linker, misaligned fiber and regions where resin has poorly wetted the fibers. Subsequently, IR thermal imaging has significantly determined fatigue damage in kenaf reinforced epoxy composites. In addition, fatigue damage modes has also been predicted and determined by the types of defects occurs due to manufacturing process. This proves that IR has successfully been a significant NDT in estimating fatigue life due to fatigue damage, proved experimentally and interpreted by the S-N curve. In terms of fatigue resistance, it is found that 60% fiber volume fraction kenaf reinforced epoxy composites specimen has the highest resistance at 119.71-53.20 MPa. Finally, based on damage accumulation, a model of fatigue life estimation, namely S-IR has been proposed

Non-destructive techniques (NDT) in composite materials

The aim of this review is to gain the information on applications and approaches that are presently available for non-destructive techniques (NDT) in composite materials. This review also will enhanced the knowledge in the NDT fields with available studies theories and research works done currently. Thus, it has been concluded the research that have been done in the past for military purpose but nowadays (NDT) technique is widely used in other various applications including composite materials, fire safety, land determine, food safety and quality and also famously practice in medical used

Fatigue life estimation of bio-composite materials

In this study, fatigue life of bio-composite materials was predicted due to manufacturing defects fatigue damage modes. Kenaf bast fibres were used to fabricate a bio-composite material with epoxy as a binding material. The bio-composites were manufactured using a hand lay-up process. The defects in the Kenaf/epoxy bio-composite were determined by a non-destructive technique using Infrared (IR) thermal imager. The thermography analyses were verified by optical microscope and scanning electron microscope (SEM) investigations. Determinations of fatigue damage has been predicted and it found that it damage has been fixed with the predicting results. Then, the Mathematical model for estimating fatigue life by IR thermal imaging technique based on damage accumulation model is proposed. This proposed model is named as S-IR thermal imaging fatigue life model

Correlation of manufacturing defects and impact behaviors of kenaf fiber reinforced hybrid fiberglass/Kevlar polyester composite

In this study, the impact properties of kenaf fibre reinforced hybrid fiberglass/Kevlar polymeric composite was investigated. In this study, a new fiber arrangement based on kenaf bast fiber as reinforcement to the hybrid fiberglass/Kevlar fiber and polyester as matrix used to fabricate the hybrid polymeric composite. Five different types of samples with different of kenaf fiber content based on volume fraction (0, 15, 45, 60 and 75%) to hybrid fiberglass/Kevlar polymer composites were manufactured. 0% of kenaf fiber has been used as control sample. The results showed that hybridization has improved the impact properties. These results were further supported through SEM micrograph of the manufacturing defects of the polymer composite. Based on literature work, manufacturing defects that occurs in composite system reduced the mechanical properties of the material. Therefore, in this research the correlation of impact behaviors and manufacturing defects of kenaf fiber reinforced hybrid fiberglass/Kevlar polymeric composite has been successfully done. As conclusion, the highest manufacturing defects determined in the composites during the fabrication significantly lowest the results of impact behavior

Review of development and characterization of sugar palm fiber reinforced polymer composites

Sugar palm fiber (SPF) has been gaining interest in the area of natural fiber composites owing to its good mechanical properties, high durability, good resistance to seawater and biodegradability. SPF is among the natural fibers that could be a potential material to be used as reinforcement in polymer composites. Incorporation of SPF as reinforcement in polymer composites has resulted in improvement in the physical, mechanical, and thermal properties of the composites. Another interesting point is the low density of SPF, which helps to reduce the weight of the composites, as well as increase the biodegradability. Much research has been carried out to determine the suitability of SPF as reinforcement in polymer composites. SPF-reinforced composites are suitable for a wide range of applications such as automotive anti-roll bars, rescue boats and drain covers. Chapter 2 provides an overview of the characteristics and development of various products derived from SPF-reinforced composites and the future direction of SPF and SPF-reinforced composites

Real and Imaginary Impedance Prediction of Ni-P Composite Coating for Additive Manufacturing Steel via Multilayer Perceptron

Mathematical models are beneficial in representing a given dataset, especially in engineering applications. Establishing a model can be used to visualise how the model fits the dataset, as was done in this research. The Levenberg–Marquardt model was proposed as a training algorithm and employed in the backpropagation algorithm or multilayer perceptron. The dataset obtained from a previous researcher consists of electrochemical data of uncoated and coated additive manufacturing steel with Ni-P at several testing periods. The model’s performance was determined by regression value (R) and mean square error (MSE). It was found that the R values for non-coated additive manufacturing steel were 0.9999, 1, and 1, while MSE values were 1.14 × 10−6, 2.99 × 10−7, and 5.10 × 10−7 for 0 h, 288 h, and 572 h, respectively. Meanwhile, the R values for the Ni-P coated additive manufacturing steel were 1, 1, 1, while the MSE values were 1.06 × 10−7, 1.15 × 10−8, and 6.59 × 10−8 for 0 h, 288 h, and 572 h, respectively. The high R and low values of MSE emphasise that this training algorithm has shown good accuracy. The proposed training algorithm provides an advantage in processing time due to its ability to approach second-order training speed without having to compute the Hessian Matrix