scholarly journals Energy absorption assessment of conical composite structures subjected to quasi-static loading through optimization based method

2020 ◽  
Vol 21 (1) ◽  
pp. 113
Author(s):  
Amin Bassiri Nia ◽  
Ali Farokhi Nejad ◽  
Li Xin ◽  
Amran Ayob ◽  
Mohd Yazid Yahya
Keyword(s):  
Energy Absorption ◽  
Static Loading ◽  
Composite Structures ◽  
Optimization Method ◽  
Filament Winding ◽  
Test Results ◽  
Finite Element Software ◽  
Collapse Mode ◽  
Conical Structure ◽  
Shell Geometry

The geometry of a composite frusta-conical structure with 20° apex angle was optimized using topology optimization method. The ATOM topology solver was used to perform optimization process. The structure was subjected to an axial compressive quasi-static loading where the criterion of optimization is the largest absorption of energy per unit volume. The optimization resulted in concave shell geometry with a volume reduction of 15%. To compare the effect of geometry on energy absorption capability, two types of GFRP specimen with different thickness were fabricated using filament winding and hand lay-up methods. The axial crushing test results were validated with numerical analysis using the commercial finite element software ABAQUS. The collapse mode and failure mechanism were investigated and identified. The presented methodology helps to find the better geometry instead of testing different geometries.

Experimental Investigation of Energy Absorption of ‎Partially Wrapped Thin-Walled ‎Aluminium-Glass/Epoxy Tube Subjected to Quasi-Static Loading

2017 ◽  
Vol 904 ◽  
pp. 61-67
Author(s):  
Tahir Abbas ◽  
Hamdan H. Ya ◽  
Mohamad Zaki Abdullah
Keyword(s):  
Experimental Investigation ◽  
Energy Absorption ◽  
Fiber Orientation ◽  
Static Loading ◽  
Failure Modes ◽  
Testing Machine ◽  
Filament Winding ◽  
Universal Testing ◽  
Thin Walled ◽  
Filament Winding Process

This paper describes the failure modes and energy absorption capability of partially wrapped aluminium-glass/epoxy tubes, subjected to quasi-static loading. ‎These tubes are used in aircraft and automobiles applications. Aluminium tubes were partially wrapped with 4, 6 and 8 glass/epoxy layers, using filament winding process. The 90◦ fiber orientation was used for glass/epoxy layers. Quasi-static loading of partially wrapped tubes was carried out at 5mm/min speed, using the universal ‎testing machine. The experimental results revealed that partially wrapped aluminium tubes are 42.54%, 47.77% and 28.91% more ‎efficient in energy absorption as compared to the simple aluminium tubes. Furthermore, the effect of glass/epoxy layers on ‎failure modes has also been described.

Crush Response of Polyurethane Foam-Filled Aluminium Tube Subjected to Axial Loading

2014 ◽  
Vol 875-877 ◽  
pp. 534-541 ◽  
Author(s):  
Chawalit Thinvongpituk ◽  
Nirut Onsalung
Keyword(s):  
Energy Absorption ◽  
Polyurethane Foam ◽  
Testing Machine ◽  
Axial Loading ◽  
Asymmetric Mode ◽  
Pu Foam ◽  
Universal Testing ◽  
Collapse Mode ◽  
Empty Tube ◽  
Foam Filled

In this paper, the experimental investigation of polyurethane (PU) foam-filled into circular aluminum tubes subjected to axial crushing was presented. The purpose of this study is to improve the energy absorption of aluminium tube under axial quasi-static load. The aluminium tube was made from the AA6063-T5 aluminium alloy tubes. Each tube was filled with polyurethane foam. The density of foam was varied from 100, 150 and 200 kg/mP3P including with empty tube. The range of diameter/thickness (D/t) ratio of tube was varied from 15-55. The specimen were tested by quasi-static axial load with crush speed of 50 mm/min using the 2,000 kN universal testing machine. The load-displacement curves while testing were recorded for calculation. The mode of collapse of each specimen was analyzed concerning on foam density and the influence of D/t ratio. The results revealed that the tube with foam-filled provided significantly increment of the energy absorption than that of the empty tube. While the density of foam and D/t ratios increase, the tendency of collapse mode is transformed from asymmetric mode to concertina mode.

scholarly journals Test and Numerical Model of Curved Steel–Concrete Composite Box Beams under Positive Moments

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2978
Author(s):  
Zhi-Min Liu ◽  
Xue-Jin Huo ◽  
Guang-Ming Wang ◽  
Wen-Yu Ji
Keyword(s):  
Finite Element ◽  
Static Loading ◽  
Composite Beams ◽  
Parameter Analysis ◽  
Outer Side ◽  
Finite Element Models ◽  
Test Results ◽  
Rotational Angle ◽  
Shear Connection ◽  
Box Beams

Compared with straight steel–concrete composite beams, curved composite beams exhibit more complicated mechanical behaviors under combined bending and torsion coupling. There are much fewer experimental studies on curved composite beams than those of straight composite beams. This study aimed to investigate the combined bending and torsion behavior of curved composite beams. This paper presents static loading tests of the full elastoplastic process of three curved composite box beams with various central angles and shear connection degrees. The test results showed that the specimens exhibited notable bending and torsion coupling force characteristics under static loading. The curvature and interface shear connection degree significantly affected the force behavior of the curved composite box beams. The specimens with weak shear connection degrees showed obvious interfacial longitudinal slip and transverse slip. Constraint distortion and torsion behavior caused the strain of the inner side of the structure to be higher than the strain of the outer side. The strain of the steel beam webs was approximately linear. In addition, fine finite element models of three curved composite box beams were established. The correctness and applicability of the finite element models were verified by comparing the test results and numerical calculation results for the load–displacement curve, load–rotational angle curve, load–interface slip curve, and cross-sectional strain distribution. Finite element modeling can be used as a reliable numerical tool for the large-scale parameter analysis of the elastic–plastic mechanical behavior of curved composite box beams.

scholarly journals An Optimization Method for the Configuration of Inter Array Cables for Floating Offshore Wind Farm

2017 ◽  
Author(s):  
Yann Poirette ◽  
Martin Guiton ◽  
Guillaume Huwart ◽  
Delphine Sinoquet ◽  
Jean Marc Leroy
Keyword(s):  
Wind Farm ◽  
Optimization Problem ◽  
Initial Point ◽  
Trust Region ◽  
Optimization Method ◽  
Global Optimum ◽  
Offshore Wind ◽  
Finite Element Software ◽  
Constrained Problems ◽  
Floating Offshore Wind Turbines

IFP Energies nouvelles (IFPEN) is involved for many years in various projects for the development of floating offshore wind turbines. The commercial deployment of such technologies is planned for 2020. The present paper proposes a methodology for the numerical optimization of the inter array cable configuration. To illustrate the potential of such an optimization, results are presented for a case study with a specific floating foundation concept [1]. The optimization study performed aims to define the least expensive configuration satisfying mechanical constraints under extreme environmental conditions. The parameters to be optimized are the total length, the armoring, the stiffener geometry and the buoyancy modules. The insulated electrical conductors and overall sheath are not concerned by this optimization. The simulations are carried out using DeepLines™, a Finite Element software dedicated to simulate offshore floating structures in their marine environment. The optimization problem is solved using an IFPEN in-house tool, which integrates a state of the art derivative-free trust region optimization method extended to nonlinear constrained problems. The latter functionality is essential for this type of optimization problem where nonlinear constraints are introduced such as maximum tension, no compression, maximum curvature and elongation, and the aero-hydrodynamic simulation solver does not provide any gradient information. The optimization tool is able to find various local feasible extrema thanks to a multi-start approach, which leads to several solutions of the cable configuration. The sensitivity to the choice of the initial point is demonstrated, illustrating the complexity of the feasible domain and the resulting difficulty in finding the global optimum configuration.

Towards the Development of Filament Wound Composite Structures Submitted to Very High Internal Pressure, Based on Complex Geometry Shapes

2013 ◽  
Author(s):  
Erik Vargas Rojas ◽  
David Chapelle ◽  
Dominique Perreux
Keyword(s):  
Internal Pressure ◽  
Composite Structures ◽  
Complex Geometry ◽  
Industrial Applications ◽  
Filament Winding ◽  
Complex Geometries ◽  
Filament Wound ◽  
Complex Shapes ◽  
Filament Wound Composite ◽  
High Internal Pressure

Industrial applications, especially composite structures bearing high internal pressure, and fabricated using the filament winding process face certain difficulties like the reinforcement of complex shapes, as well as the correct placement of fibers over the surface of a mandrel. In some cases the definition of the manufacturing parameters respond more to cost or time criteria rather than engineering standards, reducing largely the advantages of the said manufacturing process. In order to overcome these obstacles, this research aims to propose a solution that permits to fabricate complex shapes with the desired winding angles at a certain region of complex-shaped mandrels. A numerical tool that simulates the placement of fiber tows over the surface of complex geometries is developed and validated by means of the fabrication of convex and concave composite structures using detachable mandrels. Previous results show that it is feasible to wind complex geometries with good accuracy.

scholarly journals An enhanced krill herd optimization technique used for classification problem

2021 ◽  
Vol 30 (2) ◽  
pp. 354-364
Author(s):  
Firas Al-Mashhadani ◽  
Ibrahim Al-Jadir ◽  
Qusay Alsaffar
Keyword(s):  
Machine Learning ◽  
Simulated Annealing ◽  
Optimization Technique ◽  
Optimization Method ◽  
Classification Problem ◽  
Test Results ◽  
Internal Evaluation ◽  
Evaluation Measures ◽  
Search Optimization ◽  
Krill Herd

In this paper, this method is intended to improve the optimization of the classification problem in machine learning. The EKH as a global search optimization method, it allocates the best representation of the solution (krill individual) whereas it uses the simulated annealing (SA) to modify the generated krill individuals (each individual represents a set of bits). The test results showed that the KH outperformed other methods using the external and internal evaluation measures.

scholarly journals Compressive Property of an Auxetic-Knitted Composite Tube Under Quasi-Static Loading

2020 ◽  
Vol 20 (2) ◽  
pp. 101-109 ◽  
Author(s):  
Andrews Boakye ◽  
Rafui King Raji ◽  
Pibo Ma ◽  
Honglian Cong
Keyword(s):  
Energy Absorption ◽  
Compression Test ◽  
Impact Loading ◽  
Static Loading ◽  
Fiber Content ◽  
Compressive Property ◽  
Static Compression ◽  
Arrow Head ◽  
Composite Tube ◽  
Quasi Static Compression

AbstractThis research investigates the compressive property of a novel composite based on a weft-knitted auxetic tube subjected to a quasi-static compression test. In order to maximize the influence of the fiber content on the compression test, a Kevlar yarn was used in knitting the tubular samples using three different auxetic arrow-head structures (i.e. 4 × 4, 6 × 6 and 8 × 8 structure). A quasi-static compression test was conducted under two different impact loading speeds (i.e. 5 mm/min and 15 mm/min loading speed). The results indicate that the energy absorption (EA) property of the auxetic composite is highly influenced by the auxeticity of the knitted tubular fabric.

scholarly journals Aluminium Foams in the Design of Transport Means

1970 ◽  
Vol 24 (4) ◽  
pp. 295-304 ◽  
Author(s):  
Krešimir Grilec ◽  
Gojko Marić ◽  
Katica Miloš
Keyword(s):  
Energy Absorption ◽  
Mechanical Energy ◽  
Aluminium Foam ◽  
Test Machine ◽  
Test Results ◽  
Compression Tests ◽  
Compression Behaviour ◽  
Low Weight ◽  
Good Energy ◽  
The Impact

The requirements for weight reduction and improvement of performances in the design of transport means are often in contradiction to the requirements for increased safety. One of the possible ways of meeting these requirements is the application of metal foams. Thanks to cellular structure of aluminium foam along with low weight, the capability of noise and vibration damping, they feature also excellent capabilities of absorbing impact energy. Their application in the production of impact-sensitive elements of mobile or stationary transport means has significantly contributed to the reduction of the impact or collision consequences.The focus of this paper is on improving the energy absorption characteristics of aluminium foams considering the significance of their application for the technology of traffic and transport.The paper analyzes the influence of the chemical composition and density on the compression behaviour of aluminium foam. The aluminium foam samples were produced from Alulight precursor. The capability of samples to absorb mechanical energy has been estimated according to the results of compression tests. The tests were performed on a universal test machine. The test results showed that aluminium foams feature good energy absorption and the absorption capability decreases with the foam density. The Alulight AlMgSi 0.6 TiH2 - 0.4 foam can absorb more energy than Alulight AlSi 10 TiH2 – 0.8 foam.

Numerical Simulation of the Kinetic Energy Projectile Oblique Penetration into the Concrete

2014 ◽  
Vol 989-994 ◽  
pp. 982-985
Author(s):  
Jun Chen ◽  
Xiao Jun Ye
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Kinetic Energy ◽  
Three Dimensional ◽  
Test Results ◽  
Destruction Process ◽  
3D Finite Element ◽  
Finite Element Software ◽  
Simulation Results ◽  
Target Characteristics

ANSYS-LS/DYNA 3D finite element software projectile penetrating concrete target three-dimensional numerical simulation , has been the target characteristics and destroy ballistic missile trajectory , velocity and acceleration and analyze penetration and the time between relationship , compared with the test results , the phenomenon is consistent with the simulation results. The results show that : the destruction process finite element software can better demonstrate concrete tests revealed the phenomenon can not be observed , estimated penetration depth and direction of the oblique penetration missile deflection .

Micro-Testing While Drilling for Rate of Penetration Optimization: Experiments and Simulations

2021 ◽  
pp. 1-49
Author(s):  
Magnus Nystad ◽  
Bernt Aadnoy ◽  
Alexey Pavlov
Keyword(s):  
Optimization Method ◽  
Extremum Seeking ◽  
Constraint Handling ◽  
Drilling Process ◽  
Test Results ◽  
Rate Of Penetration ◽  
Drilling Rig ◽  
Model Free ◽  
Drilling Parameters ◽  
Weight On Bit

Abstract The Rate of Penetration (ROP) is one of the key parameters related to the efficiency of the drilling process. Within the confines of operational limits, the drilling parameters affecting the ROP should be optimized to drill more efficiently and safely, to reduce the overall cost of constructing the well. In this study, a data-driven optimization method called Extremum Seeking (ES) is employed to automatically find and maintain the optimal Weight on Bit (WOB) which maximizes the ROP. The ES algorithm is a model-free method which gathers information about the current downhole conditions by automatically performing small tests with the WOB and executing optimization actions based on the test results. In this paper, this optimization method is augmented with a combination of a predictive and a reactive constraint handling technique to adhere to operational limitations. These methods of constraint handling within ES application to drilling are demonstrated for a maximal limit imposed on the surface torque, but the methods are generic and can be applied on various drilling parameters. The proposed optimization scheme has been tested with experiments on a downscaled drilling rig and simulations on a high-fidelity drilling simulator of a full-scale drilling operation. The experiments and simulations show the method's ability to steer the system to the optimum and to handle constraints and noisy data, resulting in safe and efficient drilling at high ROP.

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