scholarly journals Application of Evolutionary Computation in Automotive Powertrain Mount Tuning

2006 ◽  
Vol 13 (2) ◽  
pp. 85-102 ◽  
Author(s):  
Anab Akanda ◽  
Chandu Adulla
Keyword(s):  
Finite Element ◽  
Evolutionary Computation ◽  
Optimization Problem ◽  
Design Parameters ◽  
Production Environment ◽  
Finite Element Software ◽  
Starting Point ◽  
Gradient Based ◽  
Engine Mount ◽  
Idle Shake

Engine mount tuning is a multi-disciplinary exercise since it affects Idle-shake, Road-shake and power-train noise response. Engine inertia is often used as a tuned absorber for controlling suspension resonance related road-shake issues. Last but not least, vehicle ride and handling may also be affected by mount tuning. In this work, Torque-Roll-Axis (TRA) decoupling of the rigid powertrain was used as a starting point for mount tuning. Nodal point of flexible powertrain bending was used to define the envelop for transmission mount locations. The frequency corresponding to the decoupled roll mode of the rigid powertrain was then adjusted for idle-shake and road-shake response management.A TRA decoupling procedure, cast as a multi-objective optimization problem, was applied to a body-on-frame sport-utility vehicle powertrain system. In addition to a standard gradient based optimization algorithm, available in commercial finite element software, an evolutionary computation paradigm known as Evolutionary Strategies (ES) was used to solve the optimization problem. The primary advantages of evolutionary computation over gradient based algorithms are as follows: i) They are less likely to get trapped in local minima and less dependent on initial values of the design parameters and therefore able to handle multi-modal optimization problems unlike gradient based algorithms, ii) They produce a population of viable solutions, unlike gradient based algorithms which yields a single solution. The second advantage is very attractive in a production environment since packaging and other multi-disciplinary constraints often require multiple quality solutions for the same problem. The process outlined in this work was verified by exercising a full-vehicle finite element model. The process produced a set of production feasible powertrain mount parameters for acceptable idle and road shake performance.

scholarly journals Parameter Identification in Nonlinear Mechanical Systems with Noisy Partial State Measurement Using PID-Controller Penalty Functions

Mathematics ◽  
2020 ◽  
Vol 8 (7) ◽  
pp. 1084 ◽  
Author(s):  
R. Manikantan ◽  
Sayan Chakraborty ◽  
Thomas K. Uchida ◽  
C. P. Vyasarayani
Keyword(s):  
Pid Controller ◽  
Optimization Problem ◽  
Mechanical Systems ◽  
Global Optimum ◽  
Magnetorheological Damper ◽  
Local Optimum ◽  
Nonlinear Mechanical ◽  
Gradient Based ◽  
Engine Mount ◽  
Nonlinear Mechanical Systems

Dynamic models of physical systems often contain parameters that must be estimated from experimental data. In this work, we consider the identification of parameters in nonlinear mechanical systems given noisy measurements of only some states. The resulting nonlinear optimization problem can be solved efficiently with a gradient-based optimizer, but convergence to a local optimum rather than the global optimum is common. We augment the dynamic equations with a morphing parameter and a proportional–integral–derivative (PID) controller to transform the objective function into a convex function; the global optimum can then be found using a gradient-based optimizer. The morphing parameter is used to gradually remove the PID controller in a sequence of steps, ultimately returning the model to its original form. An optimization problem is solved at each step, using the solution from the previous step as the initial guess. This strategy enables use of a gradient-based optimizer while avoiding convergence to a local optimum. The efficacy of the proposed approach is demonstrated by identifying parameters in the van der Pol–Duffing oscillator, a hydraulic engine mount system, and a magnetorheological damper system. Our method outperforms genetic algorithm and particle swarm optimization strategies, and demonstrates robustness to measurement noise.

Teeth-Number Synthesis of an Automatic Planetary Transmission Using Evolutionary Computation

2004 ◽  
Author(s):  
P. A. Simionescu ◽  
D. G. Beale ◽  
G. V. Dozier
Keyword(s):  
Constrained Optimization ◽  
Objective Function ◽  
Evolutionary Computation ◽  
Optimization Problem ◽  
Design Parameters ◽  
Constrained Optimization Problem ◽  
Gear Teeth ◽  
Estimation Of Distribution ◽  
Number Synthesis ◽  
Planetary Transmission

The gear-teeth number synthesis of an automatic planetary transmission used in automobiles is formulated as a constrained optimization problem that is solved with the aid of an Estimation of Distribution Algorithm. The design parameters are the teeth number of each gear, the number of multiple planets and gear module, while the objective function is defined based on the departure between the imposed and the actual gear ratios, constrained by teeth-undercut avoidance, limiting the maximum overall diameter of the transmission and ensuring proper planet spacing.

Analysis of Influence of Design Parameters on Ultimate Bearing Capacity of the Steel Spatial Tubular Joint

2011 ◽  
Vol 243-249 ◽  
pp. 294-297
Author(s):  
Rui Tao Zhu
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Bearing Capacity ◽  
Plate Thickness ◽  
Ultimate Bearing Capacity ◽  
Design Parameters ◽  
Finite Element Software ◽  
Computing Model ◽  
Tubular Joint ◽  
The Impact

Utilizing general finite element software ANSYS, the finite element computing model of the steel spatial tubular joint is built, which is used to analyze the mechanical properties under dead loads through changing its design parameters. According to the obtained and compared consequences, the different design parameters including stiffening ring thickness, cross-shaped ribbed plate thickness and stiffening ring length exert different influence on ultimate bearing capacity of the steel spatial tubular joint. Specifically, the ultimate bearing capacity under dead loads is affected by setting stiffening ring and changing cross-shaped ribbed plate thickness significantly. In contrast, if the thickness and length of stiffening ring are changed, the impact is insignificant. The results and conclusion can provide reference which is useful to optimize the design of steel spatial tubular joint in such category.

scholarly journals Numerical analysis of concrete-filled spiral welded stainless steel tubes subjected to compression

2018 ◽  
Author(s):  
Dongxu Li ◽  
Brian Uy ◽  
Farhad Aslani ◽  
Chao Hou
Keyword(s):  
Finite Element ◽  
Stainless Steel ◽  
Finite Element Model ◽  
Mechanical Performance ◽  
Load Capacity ◽  
Element Model ◽  
Experimental Program ◽  
Design Parameters ◽  
Steel Tubes ◽  
Finite Element Software

Spiral welded stainless tubes are produced by helical welding of a continuous strip of stainless steel. Recently, concrete-filled spiral welded stainless steel tubes have found increasing application in the construction industry due to their ease of fabrication and aesthetic appeal. However, an in-depth understanding of the behaviour of this type of structure is still needed due to the lack of proper design guidance and insufficient experimental verification. In this paper, the mechanical performance of concrete-filled spiral welded stainless steel tubes will be numerically investigated with a commercial finite element software package, through which an experimental program can be designed properly. Specifically, the proposed finite element models take into account the effects of material and geometric nonlinearities. Moreover, the initial imperfections of stainless steel tubes and the form of helical welding will be appropriately included. Enhancement of the understanding of the analysis results can be achieved by extending results through a series of parametric studies based on the developed finite element model. Thus, the effects of various design parameters will be further evaluated by using the developed finite element model. Furthermore, for the purposes of wide application of such types of structure, the accuracy of the behaviour prediction in terms of ultimate strength based on current design codes will be studied. The authors herein compared the load capacity between the finite element analysis results and the existing codes of practice.

Analysis of the Worst Mistuning Patterns in Bladed Disk Assemblies

2003 ◽  
Vol 125 (4) ◽  
pp. 623-631 ◽  
Author(s):  
E. P. Petrov ◽  
D. J. Ewins
Keyword(s):  
Finite Element ◽  
Large Scale ◽  
Optimization Problem ◽  
Element Model ◽  
Design Parameters ◽  
Finite Element Models ◽  
Bladed Disks ◽  
Bladed Disk ◽  
The Many

The problem of determining the worst mistuning patterns is formulated and solved as an optimization problem. Maximum resonant amplitudes searched across the many nodes of a large-scale finite element model of a mistuned bladed disk and across all the excitation frequencies in a given range are combined into an objective function. Individual blade mistuning is controlled by varying design parameters, whose variation range is constrained by manufacture tolerances. Detailed realistic finite element models, which have so far only been used for analyzing tuned bladed disks, are used for calculation of the forced resonant response of mistuned assemblies and for determination of its sensitivity coefficients with respect to mistuning variation. Results of the optimum search of mistuning patterns for some practical bladed disks are analyzed and reveal higher worst cases than those found in previous studies.

Layout Optimization of a Multiple Pinned Joint Under Bending in a Limited Contact Area

2013 ◽  
Author(s):  
Amir Mohsen Hejazi ◽  
Mohammad Pourgol Mohammad
Keyword(s):  
Genetic Algorithm ◽  
Finite Element ◽  
Stress Concentration ◽  
Stress Analysis ◽  
Optimization Problem ◽  
Optimization Problems ◽  
Optimization Methods ◽  
Limited Area ◽  
Design Factor ◽  
Finite Element Software

Layout determination of connectors in different mechanical configurations improves the design characteristics. The issue has recently become more practical in sensitive industries, especially in montage processes. Since connections are under different loads like bending, the layout of connection should be considered as an effective design factor in different loading conditions which is itself a step forward in achieving the optimized connection and also increases the connection life. This paper analyses the layout effects in a multiple pinned joint under bending in a limited area. The goal is to minimize the average stress and having a uniform stress distribution in the connections in order to prevent the failure inducing effect of stress concentration. The common method for solving these optimization problems is to couple two finite element numerical stress analysis software with an optimization tool or independent software which is a highly time consuming method due to enormous volume of the calculations in each iteration. In this paper the optimization problem is mathematically modeled and solved using Genetic Algorithm (GA). Genetic algorithm is found applicable here due to nonlinear behavior and complexity of the objective function in the optimization problem where analytical optimization methods are not useful. The validation results of stress analysis are obtained using finite element software. The optimized connections have longer lifetime and can carry higher loads because of degraded effects of stress concentration and minimized stresses.

Analysis of the Worst Mistuning Patterns in Bladed Disc Assemblies

2001 ◽  
Author(s):  
E. P. Petrov ◽  
D. J. Ewins
Keyword(s):  
Finite Element ◽  
Large Scale ◽  
Optimization Problem ◽  
Element Model ◽  
Design Parameters ◽  
Finite Element Models ◽  
Resonant Response ◽  
Variation Range ◽  
The Many

In the paper, the problem of determining of the worst mistuning patterns is formulated and solved as an optimization problem. Maximum resonant amplitudes searched across the many nodes of a large-scale finite element model of a mistuned bladed disc and across all the excitation frequencies in a given range are combined into an objective function. Individual blade mistuning is controlled by varying design parameters, whose variation range is constrained by manufacture tolerances. Detailed realistic finite element models, which have so far only been used for analysing tuned bladed discs, are used for calculation of the forced resonant response of mistuned assemblies and for determination of its sensitivity coefficients with respect to mistuning variation. Results of the optimum search of mistuning patterns for some practical bladed discs are analysed and reveal higher worst cases than those found in previous studies.

scholarly journals Optimization of Microextrusion Preforming Using Taguchi Method

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Shao-Yi Hsia
Keyword(s):  
Finite Element ◽  
Taguchi Method ◽  
True Strain ◽  
Strain Curve ◽  
Design Parameters ◽  
Minimum Diameter ◽  
Finite Element Software ◽  
Good Identification ◽  
3D Software ◽  
Potential Tool

Micropin head geometry significantly influences surface contact and electrical conductivity. In this paper, the preforming process of extrusion is investigated to establish it as a viable process for microforming. Here, the numerical simulations using DEFORM-3D software are used to examine the effect of preformance and pin shape on the extrusion of microbrass pins with a minimum diameter of 0.88 mm under several design parameters. These parameters are planned with the Taguchi method and help to discover better conditions for the minimum extrusion loads. For obtaining the required parameters to enable the finite element software, a compression test is first performed to determine the true stress and true strain curve of the materials. The result acquired from the experiment is compared with the simulation outcome and verified the accuracy. The consequences show that the optimal microextrusion forming conditions appear on stage rod length 0.015 mm, extruding angle 60°, upper front-end taper 60°, and bottom stage angle 60° to minimalize the forming load, and the dimensions of the deformed micropin reveal a good identification with the simulation. The study hence shows a potential tool for the combination of Taguchi method and finite element software to analyze the microforming process in the fastener industry.

Probabilistic Design Optimization of Frequency Dispersion for Rotating Blades

2010 ◽  
Author(s):  
Liqiang An ◽  
G. Gary Wang ◽  
Zhangqi Wang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Design Optimization ◽  
Optimization Problem ◽  
Frequency Dispersion ◽  
Probabilistic Constraints ◽  
Design Parameters ◽  
Probabilistic Design ◽  
Rotating Blades ◽  
Element Method

In this paper, a probabilistic design optimization method based on finite element method is proposed to calculate the variability of design parameters subject to a specified dispersion of natural frequencies of rotating blades. The element stiffness and mass matrices are derived using a two-stage finite element method and numerical integration. Based on the perturbation technology, the sensitivity of the frequencies, as well as relationship between the frequency dispersion and the coefficient of variability (CV) of the design parameters can be obtained. Such sensitivity information is then used to convert the probabilistic design optimization problem into a deterministic optimization problem. Two case studies are given to illustrate the proposed method. From the results, it is concluded that rotation of blade changes the sensitivity of CV to the design parameters considered, and using the proposed method can transform the probabilistic constraints to deterministic constraints.

A New Approach for Predicting Residence Time Distribution of Subsurface Wastewater Infiltration System

2012 ◽  
Vol 518-523 ◽  
pp. 1720-1723
Author(s):  
Jin Feng Dong ◽  
Yue Zhang ◽  
Wei Yu Zhang
Keyword(s):  
Finite Element ◽  
Residence Time ◽  
Time Distribution ◽  
Residence Time Distribution ◽  
Design Stage ◽  
Design Parameters ◽  
Two Dimensional ◽  
Hydraulic Residence Time ◽  
New Approach ◽  
Finite Element Software

Hydraulic residence time (HRT) is one of the key design parameters controlling the removal efficiency of contaminants and nutrients in subsurface wastewater infiltration system (SWIS). A two-dimensional axisymetric finite element software called SEEP/W was used to simulate unsaturated and saturated flow within SWIS. The paper presents a methodology by example for estimating residence time distribution (RTD) at the design stage of SWIS.

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