Thermal stress analysis of functionally graded disc with variable thickness due to linearly increasing temperature load

In this study, the elastic stress analysis of a hollow disk made of functionally graded materials was subjected to a linearly increasing temperature distribution. These disks have many applications in the aerospace industry, such as gas turbines and break disks. Their life cycle can increase when the stress components are minimized. A functionally graded (FG) disk with variable thickness under a linearly increasing temperature distribution is considered in this paper. The calculation program was prepared by the authors using MATLAB 7.1®. The changes in stresses and displacements according to both gradient parameters and thickness profiles were investigated and presented. The results show that gradient parameters and thickness profiles play an important role in determining the thermal responses of FG disks and in determining an optimal design of these structures. © 2013 King Fahd University of Petroleum and Minerals

Thermal stress analysis of functionally graded disc with variable thickness due to linearly increasing temperature load

In this study, the elastic stress analysis of a hollow disk made of functionally graded materials was subjected to a linearly increasing temperature distribution. These disks have many applications in the aerospace industry, such as gas turbines and break disks. Their life cycle can increase when the stress components are minimized. A functionally graded (FG) disk with variable thickness under a linearly increasing temperature distribution is considered in this paper. The calculation program was prepared by the authors using MATLAB 7.1®. The changes in stresses and displacements according to both gradient parameters and thickness profiles were investigated and presented. The results show that gradient parameters and thickness profiles play an important role in determining the thermal responses of FG disks and in determining an optimal design of these structures. © 2013 King Fahd University of Petroleum and Minerals

A comprehensive study on the deformation behavior of hadfield steel sheets subjected to the drop weight test: Experimental study and finite element modeling

This work presents the results of experimental and finite element modeling studies of impact behavior on the response of a high content of manganese steel blanks with a 1.2 mm thickness of sheets, known also commercially as Hadfield steel (an austenitic structure with a basic composition containing C 1.2% and Mn 12%). The study was done with a standard drop weight test device under certain variable parameters (velocity: 3 m/s and 5 m/s and temperature: room temperature, 70° C, 100° C, and 140° C). In this study, the evolution of force and energy values were analyzed depending on the time in the case of impact. Special care was given to the evolution of peak stress counters of finite element simulation for different temperatures. The results of the force-time, energy-time, and force-displacement curves under different temperatures and impact velocities are compared experimentally and numerically. Then the discussion are built on the effect of the operational parameters on the damage behavior of this steel. Both of these works (experimental and finite element modeling) were compared and highly satisfying results were obtained. © 2018 by the authors. Licensee MDPI, Basel, Switzerland.Acknowledgments: This study was partially supported by CNPq-CAPES/-SP-BRAZIL in the frame of common project carried out by Supmeca-Paris, UNICAMP-Campinas/SP-Brazil. The authors would like to thank sincerely for this encouragement

Experimental and numerical analysis of low velocity impact on a preloaded composite plate

An experimental and numerical study on the influence of biaxial preloading on the low velocity impact performance of E-glass/epoxy-laminated composite plates was conducted. For this aim, an experimental device was developed to apply the load in two perpendicular directions. Three preload cases, representative of actual structures were selected, biaxially tension, compression and, tension-compression (shear) loading cases. The samples were produced from unidirectional reinforced E-glass and epoxy, by using a hand lay-up technique. Laminated E-glass/epoxy with stacking sequence [0/90]2s, dimensions were 140 × 140 mm2 and a thickness of 2 mm for the samples used. Finite element analysis (FEA) was developed, using Hashin failure criteria for the composite material, and material models implemented by a User Material Subroutine into ABAQUS®/explicit software, in order to simulate the failure mechanisms and force-time histories. Force-time and energy-time data were obtained by means of user material subroutine from the finite element model. The finite element results showed a good correlation to the experimental data in terms of force-time, energy-time graph or failure in composite plate, although these numerical results strongly depended on simulation parameters like mesh size or the number of element. © 2015 Elsevier Ltd. All rights reserved.105M195The authors would like to thank The Science and Technological Research Council of Turkey (TUBITAK) for the financial support of this work, Grant number is 105M195

Experimental and numerical study of alumina reinforced aluminum matrix composites: Processing, microstructural aspects and properties

Co-continuous alumina-aluminum composite materials with excellent physical and mechanical properties offer great potentials for lightweight, wear resistant, and high-temperature applications. They combine metallic properties of matrix alloys (ductility and toughness) with ceramic properties of reinforcements (high strength and high modulus), leading to greater strength in shear and compression and higher service-temperature capabilities. Composite materials prepared from a liquid-phase displacement reaction present a unique microstructure in which each phase is a continuous network penetrated by the network of the other constituent. In this study, aluminum-alumina matrix composites reinforced with glass bubbles with low thermal and electrical conductivities are presented. Different characterization techniques were used to determine physical-mechanical properties. Porosity and density measurements were carried out by means of helium gas pycnometer and basic materials parameters were compared such as effect of the sintering process, thermal conductivity, and percentage of the wax. Drop weigh tests, semi static compression tests and also scratch tests were applied to measure the general mechanical and damage behavior of these composites. Microstructural and fracture behavior were evaluated by Scanning Electron Microscopy (SEM). A three dimensional non-linear finite element model was developed for modeling the impact and compression behavior of alumina reinforced aluminum matrix composite materials. For this stage, ABAQUS/Explicit commercial program was used. The finite element results have shown a good correlation with the experimental data in terms of contact-force and energy histories and also deflection phenomena of the alumina reinforced aluminum matrix composites during the impact was observed between the experimental data. © 2016 Elsevier Ltd. All rights reserved

Investigation of experimental research on the low velocity impact damage behavior of NCF composite plates - Complas XII

In this study an experimental investigation is performed on the impact response of non-crimp fabric composite plates at room temperature. Chopped strand mat combi is used as reinforcing material and two kinds of matrix; epoxy and polyester, are also used as resin material in the composite plates. All specimens used in experiments are manufactured by vacuum assisted resin infusion method at Atard Defence and Aerospace Advanced Technology Application Research and Development Inc. An instrumented drop weight impact testing machine Instron-Dynatup 9250 HV is used for impact testing. Impact tests are performed under various impact energies ranging from initiation of damage to final perforation. Damage processes of the samples are analyzed from cross-examining load-deflection curves, energy profiling method and damaged specimens

Effect of impactor shapes on the low velocity impact damage of sandwich composite plate: Experimental study and modelling

An experimental and numerical analysis of the influence of impactor shapes on the low velocity impact performance of aluminium sandwich composite plates has been carried out. The aluminium composite panels were manufactured by using two aluminium sheets and a low density polyethylene core under heat and pressure, which shows the outstanding properties of low weight, good rigidity and impact resistance. Experimental tests were performed using drop weight test machine, samples were impacted using steel conical, ogival, hemispherical and flat impactors, all 12 mm in diameter, for different initial impact energies of 29.43 J and 44.15 J and specimen thickness of 4 mm containing three different parts (0.5 + 3.0 + 0.5). A three dimensional non-linear finite element model is developed for simulating the impact behaviour of sandwich composite plate and the ABAQUS/Explicit commercial program was used. The face sheet material aluminium alloy 3003-O of the plate was modelled as isotropic with elastic-plastic characteristics. The description of the material characteristic of the attenuator was made by means of the Johnson-Cook elastic-plastic law. The material constitutive law of the Al 3003 plates has been implemented in a user-defined subroutine UMAT. The foam core was modelled as a crushable foam material. The finite element results showed a good correlation to the experimental data in terms of contact-force histories, energy histories, absorbed energy, and failure of the sandwich composite was observed between the experimental data. © 2015 Elsevier Ltd.105M195The authors would like to thank The Science and Technological Research Council of Turkey (TUBITAK) for the financial support of this work, grant number is 105M195

Impact response of sandwiches with open-cell casting metal foam and GFRP skins

The main advantage of using sandwich structures is their high strength, high energy absorbing capacity and high bending stiffness to weight ratio. Therefore, they are unique for the applications where the light-weight design philosophy is a crucial aspect. While sandwich structures with polymeric foams have been applied for many years, recently there is a growing interest on a new generation composite sandwiches with metallic foam core. In this study, the influence of pores per inch (ppi) of the foam on low-velocity impact response of the entire panel has been investigated. The glass fibre reinforced plastic (GFRP) skins produced by vacuum bagging technique in the study were easily bonded to the foam surfaces using a commercial adhesive in order to combine the composite sandwich panel. The low-velocity impact tests are performed to the sandwiches with the combination of two different magnesium (Mg) alloy foams (having 10 pores per inch (ppi) and 20 pores per inch), and carried out by a drop test machine with different values of impact velocity ranging from 1 to 10 m/s in order to analyse its effect. The main results of the impact tests are: force-displacement curves, peak force values, absorbed energy and influence of impact velocity. © 2016, © 2016 Informa UK Limited, trading as Taylor & Francis Group