In the implementation of Carbon Nanotube Reinforced Polymer matrix Composites in structural applications, deflection and stress analysis are important considerations. In the present study, a multi scale analysis of deflection and stress analysis of carbon nanotube (CNT) reinforced polymer composite plates is presented. A micromechanics model based on the Mori-Tanaka method is developed by intro...

We introduce a new class of high-porosity microstructures, called “single-scale laminates,” made from arrays of parallel walls. They are extremal, in the sense that no stiffer structure exists with the same total mass. They are simple, in the sense of being easy to describe, and perhaps to manufacture. And they are universal: for any high-porosity microstructure there is a single-scale laminate...

This paper presents a reliability-based prediction methodology to obtain the remaining useful life of composite materials subjected to fatigue degradation. Degradation phenomena such as stiffness reduction and increase in matrix micro-cracks density are sequentially estimated through a Bayesian filtering framework that incorporates information from both multi-scale damage models and damage meas...

This work explores the physical implications of variation in fin shape and orientation that correspond to ontogenetic changes observed in sea turtles. Through the development of a bio-inspired robotic platform – CTurtle – we show that 1) these ontogenetic changes apparently occupy stable extrema for either load-bearing or high-velocity movement, and 2) mimicry of these variations in a robotic s...

This paper presents a prediction and evaluation of delamination factor in use of twist drill, candle stick drill and saw drill. The approach is based on Taguchi’s method and the analysis of variance (ANOVA). An ultrasonic C-Scan to examine the delamination of carbon fiber-reinforced plastic (CFRP) laminate is used in this paper. The experiments were conducted to study the delamination factor un...

The mechanical properties of layered Ce-TZP/Al2O3 composites with laminate and cellular morphologies have been investigated. The strength and toughness increase as the layer thickness decreases, and the amount of transformation in the Ce-TZP layer increases discontinuously at the laminate/cellular transition. Very high strengths (1.1 GPa) and toughnesses (16 MPa?m1/2) have been obtained in some...

Carbon fiber reinforced polymers strengthen steel structural elements. These structural elements are normally subjected to static, dynamic and fatigue loadings during their life-time. CFRP laminate is commonly used structures under the subjected loads. A number of focused on the characteristics of CFRP sheets members under static, dynamic and fatigue loadings. is a gap in understanding the bond...

Stacking sequence design of a composite laminate with a given set of plies is a combinatorial problem of seeking an optimal permutation. Permutation genetic algorithms optimizing the stacking sequence of a composite laminate for maximum buckling load are studied. A new permutation GA named gene±rank GA is developed and compared with an existing Partially Mapped Permutation GA, originally develo...

The resistance to destruction of spores of Bacillus subtilis var. niger hermetically sealed in various polymeric films and exposed to ethylene oxide with and without relative humidity was determined. The effect of desiccation was also determined. The order of increased resistance to sterilization with regard to type of polymeric film was found to be: polyethylene equal to polyvinyl chloride, le...

The foils laminate approach can be implemented to grow bi-directional porous pattern from both the top and bottom surfaces of an aluminum foil. It was intuitively inferred that leakage of etchant from the clamped area can be a feasible cause to have the upward pores grow in the notches of the unpolished surface. This leakage hypothesis has been disproved by the leakage blocking and triple layer...