This work demonstrates the potential of manufacturing variable-angle composite cylinders via filament winding (FW), called VAFW. The proposed design strategy allows different angles along axial direction by dividing cylinder into regions constant angle frames. Designs using two, four, or eight frames are herein investigated. A genetic algorithm is applied to optimize each for maximum buckling load. with minimum manufacturable included in study. All structures manufactured and tested under...

A reliability-based optimization framework is introduced and used to design filament-wound cylindrical shells with variable angle tow. Seven cases are investigated enable a comparison between constant-stiffness tow designs, also considering effects of thickness variation created due overlapping paths, determined using the kinematics filament winding manufacturing process. The uncertainty in considered by means metamodels constructed Kriging method. Moving search windows incorporated into...

This work proposes a novel framework able to optimise both topology and fibre angle concomitantly minimise the compliance of structure. Two different materials are considered, one with isotropic properties (nylon) another orthotropic (onyx, which is nylon reinforced chopped carbon fibres). The optimises, in same particular sub-step, first topology, second, at every element throughout domain. For material, only optimisation takes place, whereas, for solid, orientation considered. objective...

Previous studies have shown that the kagome lattice has a remarkably high fracture toughness. This architecture is one of eight semi-regular tessellations, and this work aims to quantify toughness three other unexplored lattices: snub-trihexagonal, snub-square elongated-triangular lattices. Their mode I was obtained with finite element simulations, using boundary layer technique. These simulations showed KIc snub-trihexagonal scales linearly relative density ρ̄. In contrast, lattices scale...

Measuring the geometric imperfections in cylindrical shells is a critical step necessary to create accurate numerical models that can capture imperfection-sensitive behavior of these structures. Modern composite structures, such as variable–angle filament–wound (VAFW) cylinders, have unique imperfection signature still unknown scientific community. This new class variable–stiffness structures developed by our research group combines wide tailoring capabilities with efficient...

In this paper, a Finite Element Model Updating (FEMU) procedure is developed to find the best creep parameters for filament-wound cylinders under radial compression in harsh environmental conditions. Three winding angles are considered, each three different hygrothermal The two–stage model captures i) primary through time–hardening approach whilst ii) secondary captured by Norton's law. Given high number of and complexity determining them experimentally, FEMU routine utilises an optimisation...

Stainless steel sandwich beams with a corrugated core or Y-frame have been tested in three-point bending and the role of face-sheets has assessed by considering (i) front-and-back faces present, (ii) front face present but back absent. A fair comparison between competing beam designs is made on an equal mass basis doubling thickness when The quasi-static, responses were measured under simply supported clamped boundary conditions. For both end conditions for types core, containing underwent...

The mechanical properties of seven semi-regular lattices were derived analytically for in-plane uniaxial compression and shear. These analytical expressions then validated using Finite Element simulations. Our analysis showed that one topology is stretching-dominated; two are stretching-dominated in but bending-dominated shear; four bending-dominated. To assess their potential, the these topologies compared to regular lattices. We found elastic buckling strength tessellation be 43% higher...

The properties of lattices are strongly influenced by their nodal connectivity; yet, previous studies have focused mainly on topologies with a single vertex configuration. This work investigates the potential demi-regular lattices, two configurations, to outperform existing topologies, such as triangular and kagome lattices. We used finite element simulations predict fracture toughness three elastic-brittle under modes I, II, mixed-mode loading. scales linearly relative density ρ¯,...

Honeycombs and other lattice materials have the advantage that their topology can be designed to achieve unique combinations of properties, such as high strength at low density. The work presented here is exploratory in nature: we investigated mechanical properties a two-dimensional compared its performances topologies. Analytical expressions for uniaxial stiffness compressive were developed validated against Finite Element simulations. results showed considered stiffer stronger than diamond...

Lattice materials are extremely efficient in combining high stiffness and strength at low densities. Their architecture is a periodic assembly of bars, which, most cases, all have the same length cross-section. This is, however, suboptimal since level stress not bars. To take these variations into account, we propose to design prismatic lattices with two different bar thicknesses. The ratio thicknesses introduces new parameter lattices. Analytical expressions developed capture effect this on...