scholarly journals Theoretical and Numerical Analysis of an Aluminum Foam Sandwich Structure

2020 ◽  
Vol 15 (3) ◽  
pp. 113-124
Author(s):  
Alaa Al-Fatlawi ◽  
Károly Jármai ◽  
György Kovács
Keyword(s):  
Sandwich Structure ◽  
Aluminum Foam ◽  
Face Sheet ◽  
Fiber Reinforced ◽  
Element Analysis ◽  
Design Variables ◽  
Reinforced Plastic ◽  
Size Constraints ◽  
Theoretical And Numerical Analysis ◽  
Composite Face

The aim of the research was to develop a new lightweight sandwich structure, which can be used for elements of air containers. The structure consists of aluminum foam core with fiber reinforced composite face-sheets. Nine different laminated glass or/and carbon fiber reinforced plastic face-sheet combinations were investigated. Finite element analysis of the sandwich structures was introduced. Single-objective optimization of the new sandwich structure was achieved for minimal weight. Five design constraints were considered: stiffness of the structure, face-sheet failure, core shear, face-sheet wrinkling, size constraints for design variables. The elaborated composite structure results significant weight savings due to low density.

Bearing strength of interference-fit pin joined glass fiber reinforced plastic composites

2016 ◽  
Vol 54 (12) ◽  
pp. 1579-1591 ◽  
Author(s):  
Sang-Young Kim ◽  
Bin He ◽  
Dave (Dae-Wook) Kim ◽  
Chun Sik Shim ◽  
Ha Cheol Song
Keyword(s):  
Glass Fiber ◽  
Weight Ratio ◽  
Fiber Reinforced ◽  
Static Properties ◽  
Element Analysis ◽  
Interference Fit ◽  
Glass Fiber Reinforced Plastic ◽  
Fiber Reinforced Plastic ◽  
Glass Fiber Reinforced ◽  
Reinforced Plastic

Glass fiber reinforced plastic structures are mostly used in mid-sized marine vessels due to high strength and stiffness to weight ratio, corrosion resistance, and total life cost reductions. Mechanical joints using metallic bolts, screws, and pins are commonly used for joining thick glass fiber reinforced plastic laminates. Interference-fit pin connections provide beneficial effects such as fatigue enhancement and/or prevention of moisture intrusion to the fiber reinforced composites. This numerical and experimental study aims to investigate the effect of interference-fit on the bearing stiffness and strength of pin joined glass fiber reinforced plastic. The stress and strain distributions have been investigated for bearing loading through experiments as well as a nonlinear three dimensional finite element analysis. The quasi-static properties of the pin-loaded composites with interference-fit (0.6% and 1%) are compared with the samples with transition-fit (0% of interference-fit). The radial and the tangential strains on the vicinity of the hole obtained from the FE simulation were verified with the experimental results. The radial strains on the interference-fit pin joined glass fiber reinforced plastic coupons are lower than those on the transition-fit pin joined glass fiber reinforced plastic coupons at the consistent pin displacement, resulting in enhancement of the joint stiffness per unit bearing area by interference-fit.

Lightweight Hybrid Composites of CFRP and Aluminum Foam

2015 ◽  
Vol 825-826 ◽  
pp. 482-489
Author(s):  
Christian Fiebig ◽  
Michael Koch
Keyword(s):  
Aluminum Foam ◽  
Volume Fraction ◽  
Hybrid Composites ◽  
Minimum Weight ◽  
Sandwich Composite ◽  
Sandwich Composites ◽  
Damping Properties ◽  
Fiber Reinforced ◽  
Fiber Reinforced Plastic ◽  
Reinforced Plastic

The lightweight potential of components made of fiber-reinforced plastic can be enhanced by use of sandwich composites. So far, limited dynamic properties of plastic-based foams have prevented the use of sandwich composites in machine applications. The combination of closed-cell aluminum foam (ALF) and carbon fiber reinforced plastic (CFRP) provides a solution to this obstacle. Aluminum foam is characterized by favorable damping properties with minimum weight and CFRP provides high strength and stiffness at similarly low density. This paper deals with the design of a hybrid sandwich composite and its interpretation by using customized FEM simulations.Producing this kind of a sandwich composite in an economic production process presents a major challenge. Thus, a method has been developed that prevents excessive penetration of the resin into the pores of the aluminum foam. A high volume fraction of the resin in the foamed sandwich core would increase density and negatively influence damping properties. The implementation of a barrier layer will avoid this penetration. A DoE was developed and RTM process parameters were varied with the objective of achieving the highest specific bending stiffness. In preliminary experiments the appropriate range of injection pressure, mold temperature, and pressure force was determined. Tests with a nonwoven fabric could prevent the resin from infiltrating into the aluminum foam. Mechanical properties of the sandwich composite are only marginally affected.A model was developed to calculate the obtainable sandwich composite properties. The calculation method considers both the characteristics of the aluminum foam and the CFRP anisotropy. Based on this model a reliable calculation of the applied load could be accomplished. The design of the sandwich composite was targeting at high stiffness and determination of the natural frequency. Parallel to calculations, tests on specimen were performed and the obtained results were included into the calculation as part of the material model.

Optimal fiber orientation and topology design for compliant mechanisms with fiber-reinforced composites

2016 ◽  
Vol 231 (12) ◽  
pp. 2302-2312 ◽  
Author(s):  
Xinxing Tong ◽  
Wenjie Ge ◽  
Yonghong Zhang
Keyword(s):  
Fiber Orientation ◽  
Strain Energy ◽  
Compliant Mechanisms ◽  
Linear Optimization ◽  
Topology Design ◽  
Fiber Reinforced ◽  
Element Analysis ◽  
And Topology ◽  
Glass Fiber Reinforced ◽  
Design Variables

An approach for designing compliant mechanisms with glass fiber-reinforced epoxy materials is presented to obtain the optimum fiber orientation and topology structure simultaneously in this paper. Four-node hybrid stress elements and nodal design variables are adopted to suppress the islands and checkerboard phenomenon without additive filter technology and constraint. Taking fiber orientation and relative density as design variables, minimizing the weighted linear combination of the mutual strain energy and the strain energy is considered as objective function to achieve the desired deformation and enough load-carrying capacity of compliant mechanisms with the volume constraint. The displacement field of structure is obtained by the finite element analysis, and the non-linear optimization problem is solved via the well-known method of moving asymptotes. The numerical examples of designing compliant inverters and grippers with different weighted factors are investigated to demonstrate the effectiveness of the proposed method.

scholarly journals Compressive Strength Testing of Hybrid Concrete-Filled Fiber-Reinforced Plastic Tubes Confined by Filament Winding

2021 ◽  
Vol 11 (7) ◽  
pp. 2900
Author(s):  
In-Kyu Kang ◽  
Sun-Hee Kim
Keyword(s):  
Compressive Strength ◽  
High Strength ◽  
Maximum Error ◽  
Filament Winding ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Element Analysis ◽  
Reinforced Polymer ◽  
Reinforced Plastic ◽  
Frp Tube

In this study, an experiment on compressive strength of the hybrid concrete-filled fiber-reinforced polymer (FRP) tube (CFFT) confined by filament winding was conducted to improve the longitudinal strength while considering the thickness of filament winding as a variable. A maximum error of 17% was observed when the results of performing the finite element analysis (FEA) by applying the mechanical properties of the fiber-reinforced polymer (FRP) materials suggested in previous studies were compared to those of the compressive strength experiment on the hybrid-CFFT. Moreover, a maximum error of 15% was exhibited when the results derived from the strength equation proposed by analyzing the compressive strength experiment were compared. Furthermore, the compressive strength of the hybrid-CFFT increased by up to 14% when the longitudinal compressive strength of the pre-tensioned spun high strength concrete (PHC) pile and concrete-filled tube (CFT) were compared.

scholarly journals Design of Lightweight Cutting Tools

2020 ◽  
Vol 14 (2) ◽  
pp. 326-335
Author(s):  
Andreas Häusler ◽  
◽  
Kim Torben Werkle ◽  
Walther Maier ◽  
Hans-Christian Möhring
Keyword(s):  
Metal Cutting ◽  
Structural Integrity ◽  
Cutting Tools ◽  
Acoustic Emissions ◽  
Failure Criteria ◽  
Fiber Reinforced ◽  
Forming Process ◽  
Element Analysis ◽  
Fiber Reinforced Plastic ◽  
Reinforced Plastic

Taking into account the growing demand for sophisticated cutting tools in terms of their performance, new approaches, besides the development of the tool’s cutting edge, have to be investigated and validated by physical tests. In this study, methods of topology optimization and hybrid design are adopted for cutting tools. After a quick overview of its motivations, reduction of mass, the design of load paths, and beneficial functions within tool bodies, a structured method and its application on a long shell end mill for metal cutting is described as part of a holistic approach at the system and component levels. The manufacturing of the resulting geometry is examined for additive manufacturing. The optimized structures reduce the spindle power required, especially for acceleration to the desired speed; this, in turn, decreases the energy consumption of the process. Besides bearing static and dynamic loads, composites provide the adjustable option in process-stabilizing damping. In the field of wood cutting, the cutting forces are lower than those in the machining of metals. Here, we describe a planing tool with a large overhang and the first step in its development. The finite element analysis within the software Ansys Workbench and CompositePrep/Post (ACP), the special tool for modeling reinforced structures, are utilized for preparing the layout of the tool. To ensure the structural integrity of fiber reinforced plastic (FRP), the failure criteria proposed by Puck are applied. The overhanging planing tool is clamped on one side. It shows the principles for the development of a prototype and forms the basis for tools with even larger diameters and benefits. The underlying concept of the planing tool prototype is an innovative sandwich concept, wherein sleeves are used to join metal with carbon fiber reinforced plastic (CFRP) in a micro-forming process. Besides the abovementioned advantages, the reduction of acoustic emissions in the very noisy field of wood machining is a promising application.

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