Papers by Keyword: Lay-Up

Abstract: In this article the results of stress-strain state investigation for composite airplane wing stringer with different layers stacking structures are presented. As an object of research, a stringer made of composite carbon with V-shaped cross-section is considered. Due to the stress-strain state analysis of various stringer structures, the most effective structure for stringer layers stacking is selected, both in the view of providing the most rigidity and optimal perception by the stringer the field of external loads, which are most typical for the conditions of its operation.

Abstract: Awareness on implementing sustainable construction materials has risen significantly leading to increased renewable materials used commercially. Kenaf fibers are potentially used as composite reinforcements and combined with epoxy polymer to produce an advanced engineering material that may offer superior specific stiffness (and strength) to its density. Other advantages include renewability, easy during fabrication handling stage and relatively cheaper than commercial fibers counterparts. Current project aims to investigate mechanical strength of woven fabric kenaf composites coupons with different stacking orientations. Testing series under investigation includes different lay-up types with variation of plate thickness. Mechanical testing is conducted referred to relevant code of practice and associated damage observations during testing will be recorded. It is suggested that these materials are potential to provide an alternative reinforcing materials in composite fabrications and enhanced its applicability to a greater extent in local sector.

Abstract: Composite foam sandwich tube, which is a sandwich structure, improves stability of the tube and strength for use compared with single-layer composite, and is available in civil engineering as bearing member of light weight, high strength, and corrosion resistance. Axial compression experiment was made for fiber reinforced resin matrix composite foam sandwich tube which is laid in 5 different ways, and the comparing analysis on damage models was made according to experimental phenomenon. The laws of influence is preliminarily recognized by analyzing influence to foam sandwich tube of fiber laying, modulus of fiber, three dimensional elastic modulus ratio, tube radius, tube thickness.

Abstract: The attention in natural fiber reinforced biopolymer composite materials has been rapidly growing both in terms of industrial applications and basic research. This study investigated on the effect of aging time on mechanical properties and morphological structure of thermoset protein-based composites from egg albumen reinforced by natural cotton fibres. The cotton/albumen composites (CAC) were fabricated by hands lay-up technique with 10 w/w % of fiber content. The samples were cured and aged at room temperature for different aging time from 7 to 32 days. The cotton fibres have contributed in a significant improvement in mechanical strength and toughness of the composites. Tensile strength of the composites achieved the optimum strength of 9 MPa after 21 days of aging time and constant till 32 days. As the aging time increased, impact strength of the composites also improved to some value of 20 kJ/m2. Thereby after 21 days observation, the composites show an equilibrium moisture content of 6-9 wt%, and the strength remains stable at room condition with 50-60% relative humidity (RH). Morphology studied using SEM justify that the moisture content after aging time influenced mechanical properties of the composites.

Abstract: Compressive stress-strain characteristics of carbon/epoxy laminated composites in the through-thickness direction at strain rates of over 1000/s were evaluated using the standard split Hopkinson pressure bar. Three carbon/epoxy laminated composites (i.e., unidirectional, cross-ply and woven) with almost the same thickness were tested at room temperature. Small solid cylindrical specimens were machined such that the direction of the compression loading was perpendicular to the fiber direction of the laminates. The effects of strain rate and reinforcement geometry on the secant modulus at 1% strain, ultimate compressive strength and strain, and total strain energy to failure were examined in detail.