Design Optimisation and Life Estimation of Split Hub Geometry of FSAE Car

2016 ◽  
Author(s):  
Suraj Raju ◽  
Pavan Kumar Asu Vijaya ◽  
Varun S. Kumar ◽  
Nikhil Manjunath ◽  
Harish Nagaraj
Keyword(s):  
Design Optimization ◽  
Structural Integrity ◽  
Bending Strength ◽  
Crack Nucleation ◽  
Low Cycle Fatigue ◽  
Contact Region ◽  
Screening Method ◽  
Optimization Methods ◽  
Element Analysis ◽  
Machine Elements

Hub in the car faces high vibrations and centrifugal stresses. This calls for proper design and analysis. The life cycle of any formula car should be less which is adequate for racing purpose. This work is focused in analyzing low cycle fatigue and conducting vibratory analysis of a split hub of FSAE car. Stress concentration factor is significant in machine elements which give rise to localized stresses for any change in design of surface or abrupt change in cross section. This member acts as stress riser which leads to localized stresses in turn leading to peak stresses introducing cracks. These cracks may propagate and leads to catastrophic failure of machine elements and these conditions leads to fatigue analysis to calculate life. Two approaches are employed here. Based on linear elastic finite element analysis Neuber stresses are calculated from fictive elastic results. Strain Amplitude approach is followed by Coffin-Manson equation to determine Fatigue life. The failure induced by fretting fatigue due to two contact surfaces subjected to an oscillatory loading serves as premature crack nucleation which will gradually become a prominent issue during the running of car. In some cases it reduces the life due to micro slip at the edge of contact. The split pieces of hub talk to each other and create wear which is calculated by fretting. These rotary parts call for structurally rigid geometry. Modes with relatively high mode participation factor can be readily excited by the base vibrations. Vibratory stresses arise due to engine and rotating wheels acts like excitation frequencies which may lead to possible resonance. Campbell diagram is effectively used to modify the stiffness in turn design. Also an approach is done for design optimization of fillet stresses at Sharp edges caused due to bending strength of the split pieces. Optimization of diameter, contact region, root land dimensions is done to ensure stress distribution is uniformly spread along the fillet radius on both pieces of hub which otherwise may lead to crack initiation considering all peak stresses. Design of Experiments technique and optimization methods are used to improve structural integrity by finding the peak sectional stress. Design optimization is done using screening method to ensure strength of material.

Optimization of Reactor’s Start-Up and Shutdown Procedures by Transient Thermo-Mechanical Finite Element Analysis

2018 ◽  
Author(s):  
Sang-Mo Lee ◽  
Ohgeon Kwon ◽  
Vitor Lopes Garcia
Keyword(s):  
Finite Element ◽  
Thermal Stresses ◽  
Structural Integrity ◽  
Low Cycle Fatigue ◽  
Fluid Dynamic ◽  
Flow Behavior ◽  
Operating Conditions ◽  
Element Analysis ◽  
Heating And Cooling ◽  
Start Up

Efficient refinery start-up and shutdown durations are vital in establishing prolonged productivity in refineries operating hydrotreating reactors. The benefits of efficient start up and shutdown cycles are extensive, and include considerable operational and cost reduction. Reduced start-up and shutdown cycles, however, require increased heating and cooling rates, which cause higher temperature gradients throughout the reactor vessel, consequently leading to higher thermal stresses, which may affect damage mechanisms and limit reactor’s life. The equipment’s OEM has defined guidelines for the reactor heating and cooling during start-up and shutdown cycles and any attempt to reduce the start-up and shutdown duration is usually limited by these guidelines. It is therefore necessary to carry out an engineering assessment to determine the effect of changing the start-up and shutdown procedures beyond the OEM guidelines on reactor’s life. Multiple thermo-mechanical Finite Element analyses for a series of different start-up/ shutdown procedures, including the current procedure, were carried out to determine the through-wall thermal gradient and stresses, and identify the most critical locations. In order to estimate convective heat transfer coefficients, Computational Fluid Dynamic (CFD) analysis was utilized to describe the complex fluid flow behavior of the feedstock in the presence of catalysts and internal geometry features. Low Cycle Fatigue (LCF) was adopted as a main damage mechanism to quantify the damage as a result of the changed operating conditions. It was determined that the LCF life calculated in the reactor vessel’s critical damage locations was found to be sufficiently long with respect to the frequency of start/shutdown cycles, even with operating conditions exceeding the OEM limit. Therefore, alternative guidelines were suggested to achieve the time reduction in startup/shutdown operation by increasing ramp rates without compromising structural integrity of the vessel.

scholarly journals CFRP Reinforcement and Repair of Steel Pipe Elbows Subjected to Severe Cyclic Loading

2017 ◽  
Vol 139 (5) ◽  
Author(s):  
Ioannis Skarakis ◽  
Giannoula Chatzopoulou ◽  
Spyros A. Karamanos ◽  
Nicholas G. Tsouvalis ◽  
Aglaia E. Pournara
Keyword(s):  
Cyclic Loading ◽  
Structural Integrity ◽  
Mechanical Response ◽  
Low Cycle Fatigue ◽  
Numerical Models ◽  
Strain Curve ◽  
Steel Pipe ◽  
Cyclic Plasticity ◽  
Loading Conditions ◽  
Element Analysis

In order to ensure safe operation and structural integrity of pipelines and piping systems subjected to extreme loading conditions, it is often necessary to strengthen critical pipe components. One method to strengthen pipe components is the use of composite materials. The present study is aimed at investigating the mechanical response of pipe elbows, wrapped with carbon fiber-reinforced plastic (CFRP) material, and subjected to severe cyclic loading that leads to low-cycle fatigue (LCF). In the first part of the paper, a set of LCF experiments on reinforced and nonreinforced pipe bend specimens are described focusing on the effects of CFRP reinforcement on the number of cycles to failure. The experimental work is supported by finite element analysis presented in the second part of the paper, in an attempt to elucidate the failure mechanism. For describing the material nonlinearities of the steel pipe, an efficient cyclic-plasticity material model is employed, capable of describing both the initial yield plateau of the stress–strain curve and the Bauschinger effect characterizing reverse plastic loading conditions. The results from the numerical models are compared with the experimental data, showing an overall good comparison. Furthermore, a parametric numerical analysis is conducted to examine the effect of internal pressure on the structural behavior of nonreinforced and reinforced elbows, subjected to severe cyclic loading.

A Marine Turbocharger Compressor Multi-Point 3D Design Optimization Tool

2021 ◽  
Author(s):  
Konstantinos Ntonas ◽  
Nikolaos Aretakis ◽  
Konstantinos Mathioudakis
Keyword(s):  
Diesel Engine ◽  
Design Optimization ◽  
Structural Integrity ◽  
Engine Performance ◽  
Design Tool ◽  
Optimization Process ◽  
3D Design ◽  
Element Analysis ◽  
Turbocharged Diesel Engine ◽  
Compressor Design

Abstract A marine turbocharger 3D compressor design tool, implemented on an existing marine turbocharger retrofit platform is presented. It produces 3D centrifugal compressor geometry for optimal compressor retrofit. It encompasses two modules, allowing the design process to become fully automatic. First, a 1D compressor multi-point design optimization process is carried out, aiming to provide a fast and reliable solution based on Turbocharged diesel Engine range of operation. Structural integrity is ensured by using simplified structural analysis. Dimensionless parameters are used as optimization variables, for a given nominal compressor mass flow and power. Then a CFD compressor multi-point design optimization process is carried out, producing optimized 3D compressor geometry. It complies with the Turbocharged diesel Engine range of operation, while structural integrity is ensured by using Finite Element analysis. A turbocharger compressor design case study is presented. First, a turbocharger 1D compressor design is carried out, aiming to at least reconstituting the original diesel engine performance. This first module provides a reliable compressor initial geometry for the 3D design module. A fully 3D compressor design is then performed, using a CFD-FEA optimization process, in order to provide an improved retrofitting solution. Comparison between the multi-point and the traditional one-point design method, shows that the multi-point method provides a wider SFC reduction in the range that the Diesel engine normally operates.

Performance enhancement of normal contact ratio gearing system through correction factor

2019 ◽  
Vol 13 (3) ◽  
pp. 5242-5258
Author(s):  
R. Ravivarman ◽  
K. Palaniradja ◽  
R. Prabhu Sekar
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Correction Factor ◽  
Bending Strength ◽  
Performance Enhancement ◽  
Transmission Ratio ◽  
Contact Ratio ◽  
Element Analysis ◽  
Normal Contact ◽  
Root Region

As lined, higher transmission ratio drives system will have uneven stresses in the root region of the pinion and wheel. To enrich this agility of uneven stresses in normal-contact ratio (NCR) gearing system, an enhanced system is desirable to be industrialized. To attain this objective, it is proposed to put on the idea of modifying the correction factor in such a manner that the bending strength of the gearing system is improved. In this work, the correction factor is modified in such a way that the stress in the root region is equalized between the pinion and wheel. This equalization of stresses is carried out by providing a correction factor in three circumstances: in pinion; wheel and both the pinion and the wheel. Henceforth performances of this S+, S0 and S- drives are evaluated in finite element analysis (FEA) and compared for balanced root stresses in parallel shaft spur gearing systems. It is seen that the outcomes gained from the modified drive have enhanced performance than the standard drive.

Rubber Composition–Properties Relationships during Tire Numerical Simulation and Design Optimization

2017 ◽  
Vol 45 (1) ◽  
pp. 71-84 ◽  
Author(s):  
Alexey Mazin ◽  
Alexander Kapustin ◽  
Mikhail Soloviev ◽  
Alexander Karanets
Keyword(s):  
Numerical Simulation ◽  
Design Optimization ◽  
Strain Tensor ◽  
General Purpose ◽  
Orthogonal Functions ◽  
Element Analysis ◽  
Time Investment ◽  
Footprint Analysis ◽  
Composition Properties ◽  
Nonlinear Elastic

ABSTRACT Numerical simulation based on finite element analysis is now widely used during the design optimization of tires, thereby drastically reducing the time investment in the design process and improving tire performance because it is obtained from the optimized solution. Rubber material models that are used in numerical calculations of stress–strain distributions are nonlinear and may include several parameters. The relations of these parameters with rubber formulations are usually unknown, so the designer has no information on whether the optimal set of parameters is reachable by the rubber technological possibilities. The aim of this work was to develop such relations. The most common approach to derive the equation of the state of rubber is based on the expansion of the strain energy in a series of invariants of the strain tensor. Here, we show that this approach has several drawbacks, one of which is problems that arise when trying to build on its basis the quantitative relations between the rubber composition and its properties. An alternative is to use a series expansion in orthogonal functions, thereby ensuring the linear independence of the coefficients of elasticity in evaluation of the experimental data and the possibility of constructing continuous maps of “the composition to the property.” In the case of orthogonal Legendre polynomials, the technique for constructing such maps is considered, and a set of empirical functions is proposed to adequately describe the dependence of the parameters of nonlinear elastic properties of general-purpose rubbers on the content of the main ingredients. The calculated sets of parameters were used in numerical tire simulations including static loading, footprint analysis, braking/acceleration, and cornering and also in design optimization procedures.

Tire Bead Overheating in Urban Buses and Trucks Using Drum Brake Systems

1998 ◽  
Vol 26 (1) ◽  
pp. 51-62
Author(s):  
A. L. A. Costa ◽  
M. Natalini ◽  
M. F. Inglese ◽  
O. A. M. Xavier
Keyword(s):  
Heat Transfer ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Thermal Energy ◽  
Structural Integrity ◽  
Experimental Temperature ◽  
Temperature Profiles ◽  
Element Analysis ◽  
Drum Brake ◽  
Fea Model

Abstract Because the structural integrity of brake systems and tires can be related to the temperature, this work proposes a transient heat transfer finite element analysis (FEA) model to study the overheating in drum brake systems used in trucks and urban buses. To understand the mechanics of overheating, some constructive variants have been modeled regarding the assemblage: brake, rims, and tires. The model simultaneously studies the thermal energy generated by brakes and tires and how the heat is transferred and dissipated by conduction, convection, and radiation. The simulated FEA data and the experimental temperature profiles measured with thermocouples have been compared giving good correlation.

scholarly journals Potential and limitations of finite element modelling in assessing structural integrity of coralline algae under future global change

2015 ◽  
Vol 12 (19) ◽  
pp. 5871-5883 ◽  
Author(s):  
L. A. Melbourne ◽  
J. Griffin ◽  
D. N. Schmidt ◽  
E. J. Rayfield
Keyword(s):  
Climate Change ◽  
Finite Element ◽  
Structural Integrity ◽  
Geometric Model ◽  
Algal Growth ◽  
Coralline Algae ◽  
Rocky Shores ◽  
Element Analysis ◽  
Scan Data ◽  
The Impact

Abstract. Coralline algae are important habitat formers found on all rocky shores. While the impact of future ocean acidification on the physiological performance of the species has been well studied, little research has focused on potential changes in structural integrity in response to climate change. A previous study using 2-D Finite Element Analysis (FEA) suggested increased vulnerability to fracture (by wave action or boring) in algae grown under high CO2 conditions. To assess how realistically 2-D simplified models represent structural performance, a series of increasingly biologically accurate 3-D FE models that represent different aspects of coralline algal growth were developed. Simplified geometric 3-D models of the genus Lithothamnion were compared to models created from computed tomography (CT) scan data of the same genus. The biologically accurate model and the simplified geometric model representing individual cells had similar average stresses and stress distributions, emphasising the importance of the cell walls in dissipating the stress throughout the structure. In contrast models without the accurate representation of the cell geometry resulted in larger stress and strain results. Our more complex 3-D model reiterated the potential of climate change to diminish the structural integrity of the organism. This suggests that under future environmental conditions the weakening of the coralline algal skeleton along with increased external pressures (wave and bioerosion) may negatively influence the ability for coralline algae to maintain a habitat able to sustain high levels of biodiversity.

scholarly journals Machine Learning for Design Optimization of Electromagnetic Devices: Recent Developments and Future Directions

2021 ◽  
Vol 11 (4) ◽  
pp. 1627
Author(s):  
Yanbin Li ◽  
Gang Lei ◽  
Gerd Bramerdorfer ◽  
Sheng Peng ◽  
Xiaodong Sun ◽  
...  
Keyword(s):  
Machine Learning ◽  
Design Optimization ◽  
Optimization Methods ◽  
Machine Learning Algorithms ◽  
Cloud Services ◽  
Robust Design Optimization ◽  
Support Vector ◽  
Future Directions ◽  
Electromagnetic Devices ◽  
Recent Developments

This paper reviews the recent developments of design optimization methods for electromagnetic devices, with a focus on machine learning methods. First, the recent advances in multi-objective, multidisciplinary, multilevel, topology, fuzzy, and robust design optimization of electromagnetic devices are overviewed. Second, a review is presented to the performance prediction and design optimization of electromagnetic devices based on the machine learning algorithms, including artificial neural network, support vector machine, extreme learning machine, random forest, and deep learning. Last, to meet modern requirements of high manufacturing/production quality and lifetime reliability, several promising topics, including the application of cloud services and digital twin, are discussed as future directions for design optimization of electromagnetic devices.

scholarly journals Computational and experimental mechanical performance of a new everolimus-eluting stent purpose-built for left main interventions

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Saurabhi Samant ◽  
Wei Wu ◽  
Shijia Zhao ◽  
Behram Khan ◽  
Mohammadali Sharzehee ◽  
...  
Keyword(s):  
Structural Integrity ◽  
Mechanical Performance ◽  
Experimental Studies ◽  
Patient Specific ◽  
Wall Structure ◽  
Left Main ◽  
Element Analysis ◽  
Stent Expansion ◽  
Radial Strength ◽  
Different Diameters

AbstractLeft main (LM) coronary artery bifurcation stenting is a challenging topic due to the distinct anatomy and wall structure of LM. In this work, we investigated computationally and experimentally the mechanical performance of a novel everolimus-eluting stent (SYNERGY MEGATRON) purpose-built for interventions to large proximal coronary segments, including LM. MEGATRON stent has been purposefully designed to sustain its structural integrity at higher expansion diameters and to provide optimal lumen coverage. Four patient-specific LM geometries were 3D reconstructed and stented computationally with finite element analysis in a well-validated computational stent simulation platform under different homogeneous and heterogeneous plaque conditions. Four different everolimus-eluting stent designs (9-peak prototype MEGATRON, 10-peak prototype MEGATRON, 12-peak MEGATRON, and SYNERGY) were deployed computationally in all bifurcation geometries at three different diameters (i.e., 3.5, 4.5, and 5.0 mm). The stent designs were also expanded experimentally from 3.5 to 5.0 mm (blind analysis). Stent morphometric and biomechanical indices were calculated in the computational and experimental studies. In the computational studies the 12-peak MEGATRON exhibited significantly greater expansion, better scaffolding, smaller vessel prolapse, and greater radial strength (expressed as normalized hoop force) than the 9-peak MEGATRON, 10-peak MEGATRON, or SYNERGY (p < 0.05). Larger stent expansion diameters had significantly better radial strength and worse scaffolding than smaller stent diameters (p < 0.001). Computational stenting showed comparable scaffolding and radial strength with experimental stenting. 12-peak MEGATRON exhibited better mechanical performance than the 9-peak MEGATRON, 10-peak MEGATRON, or SYNERGY. Patient-specific computational LM stenting simulations can accurately reproduce experimental stent testing, providing an attractive framework for cost- and time-effective stent research and development.

Component Low Cycle Fatigue Behavior Based on Standard Calculation Procedure and Non-Linear FEA

2017 ◽  
Author(s):  
Jürgen Rudolph ◽  
Adrian Willuweit ◽  
Steffen Bergholz ◽  
Christian Philippek ◽  
Jevgenij Kobzarev
Keyword(s):  
Power Plants ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Hybrid Approach ◽  
Combined Cycle ◽  
Cycle Fatigue ◽  
Element Analysis ◽  
Constitutive Material Model ◽  
Standard Design ◽  
Creep Fatigue

Components of conventional power plants are subject to potential damage mechanisms such as creep, fatigue and their combination. These mechanisms have to be considered in the mechanical design process. Against this general background — as an example — the paper focusses on the low cycle fatigue behavior of a main steam shut off valve. The first design check based on standard design rules and linear Finite Element Analysis (FEA) identifies fatigue sensitive locations and potentially high fatigue usage. This will often occur in the context of flexible operational modes of combined cycle power plants which are a characteristic of the current demands of energy supply. In such a case a margin analysis constitutes a logical second step. It may comprise the identification of a more realistic description of the real operational loads and load-time histories and a refinement of the (creep-) fatigue assessment methods. This constitutes the basis of an advanced component design and assessment. In this work, nonlinear FEA is applied based on a nonlinear kinematic constitutive material model, in order to simulate the thermo-mechanical behavior of the high-Cr steel component mentioned above. The required material parameters are identified based on data of the accessible reference literature and data from an own test series. The accompanying testing campaign was successfully concluded by a series of uniaxial thermo-mechanical fatigue (TMF) tests simulating the most critical load case of the component. This detailed and hybrid approach proved to be appropriate for ensuring the required lifetime period of the component.

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