Analysis of unbalanced laminate composites with imperfect interphase: Effective properties via asymptotic homogenization method

This work addresses the Asymptotic Homogenization Method (AHM) to find all the non-zero independent constants of the fourth-order elasticity tensor of a theoretically infinite periodically laminated composite. The concept of Unit Cell describes the domain, comprised of two orthotropic composite plies separated by an isotropic interphase. A general case with an unbalanced composite is considered. Thus, the coupled components of the tensor are expected. Both analytical and numerical solutions are derived. In addition, an interphase degradation model is proposed to evaluate its effect on the effective properties of the media. Two different stacking sequences are considered with five degrees of interphase imperfection each. The results show good agreement between the analytical and numerical solutions. In addition, it is clear that the more imperfect the interphase is, the more affected the effective properties of the media are, especially those dependent on the stacking direction.

Ballistic characterization of fiber elastomer metal laminate composites and effect of positioning of fiber reinforced elastomer

The present study aims at investigating the ballistic impact response of jute, natural rubber and aluminium based tri-layer composites with two different configurations, namely Aluminium-Jute-Rubber-Jute and Jute-Rubber-Jute-Aluminium. The proposed composites were fabricated using the compression moulding technique and subjected to ballistic impact testing at impact velocities of 75 m/s, 105 m/s, 154 m/s and 183 m/s. The energy absorption and damage mitigation characteristics of the proposed fibre metal elastomer tri-layer composites were assessed. Results showed that among the two proposed composites, the composite with rubber facing the impact side exhibits better energy absorption and also helps in damage mitigation compared to the composite having aluminium on the impact side. In addition, a parametric study was carried out by varying the thickness of the rubber layer. It was observed that the impact response of the proposed tri-layer composites improved with increasing thickness of the rubber layer, especially in the case of the Jute-Rubber-Jute-Aluminium configuration.

The Study of Magnetoimpedance Effect for Magnetoelectric Laminate Composites with Different Magnetostrictive Layers

The rectangular magnetoelectric (ME) composites of Metglas/PZT and Terfenol-D/PZT are prepared, and the effects of a magnetostrictive layer’s material characteristics on the magnetoimpedance of ME composite are discussed and experimentally investigated. The theoretical analyses show that the impedance is not only dependent on Young’s modulus and the magnetostrictive strain of magnetostrictive material but is also influenced by its relative permeability. Compared with Terfenol-D, Metglas possesses significantly higher magnetic permeability and larger magnetostrictive strain at quite low Hdc due to the small saturation field, resulting in the larger magnetoimpedance ratio. The experimental results demonstrate that the maximum magnetoimpedance ratios (i.e., ΔZ/Z) of Metglas/PZT composite are about 605.24% and 239.98% at the antiresonance and resonance, respectively. Specifically, the maximum ΔZ/Z of Metglas/PZT is 8.6 times as high as that of Terfenol-D/PZT at the antiresonance. Such results provide the fundamental guidance in the design and fabrication of novel multifunction devices based on the magnetoimpedance effect of ME composites.

Glazing Safety and Resilience: New High Performance Options

High performance marine glass can be characterized as a product that offers safety from accidental or intentional breakage, as well as resilience over time. The composites that fall into this category often include strengthened glass, tough, durable interlayers that bond the glass, and coatings that provide improved solar optical performance. In addition, the laminate composites deliver acoustical benefits, as well as security benefits beyond the basic safety performance of the material. This paper presents the components that comprise high performance marine glazing, the testing that the products go through, and examples of yachts and vessels that have incorporated high performance features into their glazing specifications.

Investigation on Thrust and Torque Generation During Drilling of Hybrid Laminates Composite with Different Stacking Sequences Using Multiobjective Optimization Module

This paper highlights the reinforcement of two different fibers in the manufacturing of hybrid laminate composites. The feasibility of glass and carbon fiber-based hybrid composites is proposed for various high performances due to their versatile mechanical properties. However, anisotropic and non-homogeneity nature creates several machining challenges for manufacturers. It can be regulated through the selection of proper cutting conditions during the machining test. The effect of process constraints like spindle speed (rpm), feed rate (mm/min), and stacking sequences ([Formula: see text] was evaluated for the optimum value of thrust force and Torque during the drilling test. The cost-effective method of hand layup has been used to fabricate the composites. Four different hybrid composites were developed using different layers of carbon fiber and glass fiber layers. The outcomes of variables on machining performances were analyzed by variation of feed rate and speed to acquire the precise holes in the different configurations. The application potential of the proposed composites is evaluated through the machining (drilling) efficiency. The optimal condition for the drilling procedure was investigated using the multiobjective optimization-Grey relation analysis (MOO-GRA) approach. The findings of the confirmatory test show the feasibility of the MOO-GRA module in a machining environment for online and offline quality control.

Homogenization Method to Calculate the Stiffness Matrix of Laminated Composites

New analytical models have been developed for predicting equivalent Young’s and shear moduli of laminate composites. Sets of procedures and calculations are presented in order to obtain equivalent properties in all levels, lamina and laminate. An ultimate path to predict the mechanical properties of laminated composites on the perspective of the material, orientation, and thickness has been developed. By calculating the mechanical properties using Chamis model then an Objectif function with five norms, these norms allow the mechanical properties to be examined and the ultimate answer to be predicted. Another model discusses an alternative concept of equivalent lamina elements (ELEs) by first using Chamis model for hybrid composites. Next, the ELEs are laminated in the direction and integrated into the compliance matrix for each ply. In addition, four new Generalization models for equivalence in thickness and in angle are presented in this paper. The analytical results are validated against other developed models in published articles as well as experimental results. Numerical case studies were conducted to assess the precision of results from the suggested models. The results demonstrated the capability and efficiency of the presented models for predicting the mechanical properties of multi-layer/multi-material laminate composites under different orientation conditions.