Constrained design optimization of selected mechanical system components using Rao algorithms

Optimization of needle roller bearing design using novel hybrid methods

In the design of tapered roller bearings, long life is the one of the most important criterion. The design of bearings has to satisfy constraints of geometry and strength, while operating at its rated speed. An optimal design methodology is needed to achieve this objective (i.e., the maximization of the fatigue life). The fatigue life is directly proportional to the dynamic capacity; hence, for the present case, the latter has been chosen as the objective function. It has been optimized by using a constrained nonlinear formulation with real-coded genetic algorithms. Design variables for the bearing include four geometrical parameters: the bearing pitch diameter, the diameter of the roller, the effective length of the roller, and the number of rollers. These directly affect the dynamic capacity of tapered roller bearings. In addition to these, another five design constraint constants are included, which indirectly affect the basic dynamic capacity of tapered roller bearings. The five design constraint cons...

An Optimal Design Methodology of Tapered Roller Bearings Using Genetic Algorithms

Design optimization of an angular contact ball bearing for the main shaft of a grinder

In Spherical Roller Bearings (SRBs) design the fatigue and wear lives are the most important factors. The fatigue life of bearing is connected to dynamic capacity (Cd) and wear life of bearing is linked with the elasto-hydrodynamic minimum film thickness (hmin). Multi-objective optimization (MOO) of SRBs has been considered in the present study. For SRBs optimization problem, two objectives (Cd and hmin), eight design variables, and twenty-two constraints have been considered. Bearing pitch diameter, roller diameter, number of rollers, effective roller length and the contact angle are five design geometrical variables and other three are constraint parameters. Objective functions have been optimized individually as well as simultaneously. Elitist Non Dominated Sorting Genetic Algorithm (NSGA-II) is used to solve a non-linear constrained optimization problem of the SRB design. A convergence methodology is performed to the bearing design for global optimum results. Results obtained from NSGA-II runs of MOO have been used to draw Pareto-optimal fronts (POFs). Optimum bearing dimensions are selected by considering the knee-point solution on the POFs. Results indicate that the dynamic capacity of optimized bearing got enhanced thus increase in life of the bearing. A sensitivity analysis is conducted to identify the sensitivity of objective functions with design variables. The sensitivity analysis plays an important part in deciding the tolerances, which can be provided to design variables for the manufacturing of optimized bearings. The results obtained from MOO problem have been compared with available literature and are found to be better.

Multi-objective optimization of spherical roller bearings based on fatigue and wear using evolutionary algorithm

In the design of cylindrical roller bearings, the long life is the one of the most important criterion. Bearing standards define the design space available to a designer for deciding internal geometries of the bearing. Based on the rated speed and loading conditions, the design has to satisfy constraints of geometry and strength. An optimum design methodology is needed to achieve this objective. Since the fatigue life is directly proportional to the basic dynamic capacity, for the present case it has been chosen as objective function. It has been optimized by using a constrained non-linear formulation with real-coded genetic algorithms. Design variables include four geometrical parameters: the bearing pitch diameter, the diameter of the roller, the effective length of the roller, and the number of rollers. In addition to these another five design constraint constants are included, which indirectly affect the basic dynamic capacity of cylindrical roller bearings. The five design constraint constants have b...

Development of an Optimum Design Methodology of Cylindrical Roller Bearings Using Genetic Algorithms

A generalized finite element formulation for nonlinear frequency response analysis of viscoelastic sandwich beams using harmonic balance method

AbstractA zig-zag 1–3 viscoelastic composite (VEC) layer is designed for improved passive damping treatment of the vibrating structural beam. A zig-zag 1–3 VEC comprises by incorporating graphite blocks in zig-zag manner within the conventional viscoelastic material (VEM) layer. For the estimation of its damping capacity in the passive damping treatment of a beam, the corresponding finite element (FE) model is formed. To investigate the effect of inclusions in their zig-zag form compared to regular form, primarily, the optimal dimensional properties of corresponding configurations are obtained for the maximum damping of the beam. Then, their optimal modal loss factors and the performance in controlling the forced vibration of beam are compared. The results reveal that VEC with a zig-zag form of inclusions improves damping significantly compared to their regular form and conventional VEM. Moreover, this enhancement in damping appears due to the improvement in both extensional and shear counterparts of modal loss factor.KeywordsViscoelastic materialsVibration controlFinite element methodPassive damping treatment 

R. S. Reddy

Papers

Development of an Optimum Design Methodology of Cylindrical Roller Bearings Using Genetic Algorithms

An Optimal Design Methodology of Tapered Roller Bearings Using Genetic Algorithms

A generalized finite element formulation for nonlinear frequency response analysis of viscoelastic sandwich beams using harmonic balance method

Design of Zig-Zag 1–3 Viscoelastic Composite Layer for the Improved Passive Damping Treatment of Beam

Parametric Instability Control of Porous Functionally Graded Beam using Piezoelectric Actuators