Abolfazl Khalkhali

[ 1 ] - Experimental Analysis of Crashworthiness Behavior of Energy Absorber Tubes Under 3D Oblique Load

Actual applications of the energy absorbers showed that actual loads are not applied in the form of pure axial compression, pure bending or pure torsion. In reality, an energy absorber component may be subjected to combined loading of compression, bending and torsion. A number of previous articles have investigated the behavior of energy absorbers under oblique loading. In such cases, the obliq...

[ 2 ] - تحلیل سفتی پیچشی و خمشی بدنه خودروی سواری با استفاده از مدل اجزای محدود ساده سازی شده

مدل‌‏‌‌ های ساده سازی شده ابزار مناسبی برای بهینه سازی سازه ی اصلی خودرو در مراحل اولیه طراحی می باشند. در این مقاله یک مدل ساده سازی شده از بدنه ی یک خودرو سواری سدان ارائه می شود. که در آن،اعضای اصلی حمل کننده بار مانند ستون ها ، ریل ها و اعضای اصلی سازنده کف با المان های تیر یک بعدی و پانل ها با المان های درشت جایگزین می شوند. به منظور اعتبار سنجی دقت استاتیکی مدل ساده سازی شده، سفتی پیچشی و...

[ 3 ] - طراحی پانل جانبی بدنه منفصل خودرو کلاس B و شبیه سازی اجزای محدود برخورد از جانب

تابع هدف در تصادف خودرو، مسالة‌ تغییر شکل سازة خودرو به شکلی کاملاً‌ منظم و کنترل شده بدون آسیب رسیدن به فضای سرنشین می‌باشد. به این منظور سازة خارجی محفظة سرنشین، بایستی جهت جذب انرژی تصادف و کاهش نیروی منتقل شده به سرنشینان، دچار لهیدگی گردد. در این مقاله در فرایند طراحی ابتدا طرح بدنه منفصل خودرو در نرم افزار CATIA مدل سازی شده، سپس توسط نرم‌افزار پیش پردازش Hyper mesh المان بندی شده است و در...

[ 4 ] - Multi-objective Crashworthiness Optimization of the Aluminum Foam-filled Tubes

In order to reduce both the weight of vehicles and the damage of occupants in a crash event simultaneously, it is necessary to perform a multi-objective optimization of the automotive energy absorbing components. In this paper, axial impact crushing behavior of the aluminum foam-filled thin-walled tubes are studied by the finite element method using commercial software ABAQUS. Comparison of the...

[ 5 ] - Static and modal analysis of parabolic-boundary functionalized Carbon nanotube-reinforced composite plates using FEM

This paper investigates the effect of different methods of carbon nanotubes distribution in a thin matrix on static and dynamic behavior of the nanocomposite. Five different symmetric patterns of distribution are considered, including four parabolic patterns and a linear one. For each pattern, the effective mechanical properties of the resultant nanocomposite are calculated using the rule of mi...

[ 6 ] - Admission Effects on the Flow Behaviour of a Double Entry Turbocharger Turbine

Dual turbocharger turbine is fed by an unequal out-of-phase mass flow charge almost all the time which have significant effects on its performance parameters and flow phenomena which are not well known. Besides fully understanding the flow behavior in the radial turbine suffers from lack of detailed information about the secondary flows. This article studies the secondary flow structure within ...

[ 7 ] - Static and modal analysis of parabolic-boundary functionalized Carbon nanotube-reinforced composite plates using FEM

This paper investigates the effect of different methods of carbon nanotubes distribution in a thin matrix on static and dynamic behavior of the nanocomposite. Five different symmetric patterns of distribution are considered, including four parabolic patterns and a linear one. For each pattern, the effective mechanical properties of the resultant nanocomposite are calculated using the rule of mi...

[ 8 ] - Low-Carbon Steel Sheet Asymmetric Single-Point Incremental Forming: Analysis and Optimization of the Surface Roughness (TECHNICAL NOTE)

Surface roughness (SR) has an adverse effect on the appearance of low-carbon steel parts, formed in the asymmetric incremental sheet forming (AISF) process, particularly those requiring painting operation. The purpose of this study is to investigate the effects of AISF process parameters on the surface roughness of an asymmetric part formed on low-carbon steel sheets. The parameters are feed ra...

[ 9 ] - Optimum Design of a Coir Fiber Biocomposite Tube Reinforced with Nano Silica and Nano Clay Powder

Due to significant environmental advantages, biocomposites have recently received increasing attention. In the present research, strength of hat-shaped coir fiber biocomposites tubes reinforced with nano powder was evaluated experimentally under 3-point bending tests. The tubes were manufactured using hand lay-up technique and based on Taguchi design of experiment. The effects of different para...

[ 10 ] - Intake Manifold Flow Assessment on a 3-cylinder Natural Aspirated Downsized Engine Using CFD and GT-SUITE

In this paper the intake manifold as the most effective part on engine’s volumetrice efficiency is in vestigated in detail with emphesizing on flow behavior and characterestics. The eight different design have been prepared and imported to CFD software. Five objective functions for investigation of flow have been connsidered and applied in TOPSIS with different weights. Mass flow rate,massfl...

[ 11 ] - Experimental and Numerical Flow Investigation of Intake Manifold and Multi Criteria Decision Making on 3-cylinder SI Engine using Technique for Order of Preference by Similarity to Ideal Solution (RESEARCH NOTE)

In this paper, technique for order of preference by similarity to ideal solution(TOPSIS) method is used to find the best compromising design of intake manifold for a 3-cylinder engine considering mean value of torque, torque at 3500 rpm, mean value of brake mean specific consumption (BSFC) and BSFC at 3500 rpmas four objective functions. To calculate the objective functions, engine simulation i...

[ 12 ] - Multi-objective Optimization of Hybrid Carbon/Glass Fiber Reinforced Epoxy Composite Automotive Drive Shaft

In design and fabricate drive shafts with high value of fundamental natural frequency that represented high value of critical speed; using composite materials instead of typical metallic materials could provide longer length shafts with lighter weight. In this paper, multi-objective optimization (MOP) of a composite drive shaft is performed considering three conflicting objectives: fundamental ...

[ 13 ] - Optimal Design of Sandwich Panels Using Multi-Objective Genetic Algorithm and Finite Element Method

Low weight and high load capacity are remarkable advantages of sandwich panels with corrugated core, which make them more considerable by engineering structure designers. It’s important to consider the limitations such as yielding and buckling as design constraints for optimal design of these panels. In this paper, multi-objective optimization of sandwich panels with corrugated core is carried ...

[ 14 ] - Multi-objective Optimization of a Projectile Tip for Normal Penetration

The main purpose of the present work is multi-objective shape optimization of a projectile tip for impacting and normal penetrating. Velocity drop, weight and inner volume of projectile have been considered as three conflicting objective functions. For this purpose, at the first step, finite element modeling was done using ABAQUS/Explicit and projectile penetration was examined in different ge...

[ 15 ] - Modeling and Hybrid Pareto Optimization of Cyclone Separators Using Group Method of Data Handling (GMDH) and Particle Swarm Optimization (PSO)

In present study, a three-step multi-objective optimization algorithm of cyclone separators is catered for the design objectives. First, the pressure drop (Dp) and collection efficiency (h) in a set of cyclone separators are numerically evaluated. Secondly, two meta models based on the evolved Group Method of Data Handling (GMDH) type neural networks are regarded to model the Dp and h as the re...