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Abstract This study investigated the usability of hybrid sandwich structures as facade panels. The explored sandwich structure was made of mineral-glass fibre reinforced polymer (GFRP) skins and a GFRP truss core, fabricated by means of a novel manufacturing method. The compressive and shear specific strengths of the panels were assessed and compared with a few common lightweight structures to verify that the manufactured truss core had comparable values. Three-point bending tests indicated that the polyurethane foam used (required for the manufacturing process) had negligible mechanical contribution. Full-scale panels were tested under a distributed load. The tests were simulated using the three-dimensional finite element method to predict the pressure at which mineral cracks appeared in order to avoid their occurrence in the design phase. The simulation results exhibited good agreement with experimental data, and the model was validated in terms of deflection and strain responses. The occurrence of cracks and their propagation were numerically reproduced using the concrete-damage plasticity model. The link between the connector and crack positions in the mineral skin was highlighted in this study. [ABSTRACT FROM AUTHOR]

This paper aims to present a methodology to predict the anisotropic and non-linear behaviour of glass fibre reinforced plastics using finite element methods. A material model is implemented in order to remedy the need of multiple material definitions, and to control the local plastic behaviour as a function of the fibre orientation. Injection moulding simulations traditionally provide second order orientation tensors, which are considered together with a homogenization scheme to compute local material properties. However, in the present study, fourth order tensors are used in combination with traditional methods to provide more accurate material properties. The elastic and plastic response of the material model is optimized to fit experimental test data, until simulations and experiments overlap. The proposed material model can support design engineers in making more informed decisions, allowing them to create smarter products without the need of excessive safety factors, leading to reduced component weight and environmental impact. [ABSTRACT FROM AUTHOR]

The present investigation deals with an experimental analysis of punching process of Glass Fiber Reinforced Plastics (GFRP) sheets. The process has the potential to dramatically reduce the cycle time; thus, it can be used for industrial applications where large numbers of holes are needed. However, the laminate damage represents the major concern for the employment of hole punching. Thus, a campaign of experimental tests was conducted on thin laminates with varying the punch-die clearance. In addition, drilled holes were performed in order to compare the quality and strength of the holes performed by drilling and punching processes. To assess the influence of the process parameters on the holes quality, mechanical characterization was performed by means of tensile test with central hole and bearing test. Moreover, morphological analysis was conducted to determine the quality of the punched hole and the extension of the delaminated region. According to the achieved results, the damage produced by punching process, especially when small clearances were used, is limited and comparable to that produced by drilling process. [ABSTRACT FROM AUTHOR]

An experimental investigation is presented into the explosive blast response of fibre-reinforced polymer laminates used in naval ship structures. Blast tests using plastic explosive charges were performed in air on square target plates made of carbon-polyester, glass-polyester, carbon-vinyl ester or glass-vinyl ester laminates, which are composite materials used in naval ships. The laminates were dynamically loaded by shock waves of increasing pressure and impulse, and the deformation, damage and residual mechanical properties were determined. The amount of blast-induced damage and the post-blast mechanical properties depend on both the fibre reinforcement and polymer matrix. E-glass laminates have higher resistance to blast-induced delamination cracking and tow rupture than carbon fibre composites. Furthermore, glass or carbon fibre laminates with a vinyl ester matrix have superior blast damage resistance compared to composites with a polyester matrix. The higher damage resistance is attributed to the higher flexural strain energy capacity and interlaminar fracture toughness properties of laminates containing glass fibres or vinyl ester matrix. [ABSTRACT FROM AUTHOR]