FE Simulation and Experimental Validation of A Shear Spinning Process using the Orthogonal Optimization Method

With the use of an idealized model of the shear spinning process some of the basic quantities in the shearing mechanism have been defined and formulated, these being: shear strain, shear strain rate, specific energy, and tangential force (torque) in spinning. An experimental technique to study metal flow in shear spinning has been described. The results of analytical work have been compared with experimental data.

Download Full-text

Plastic Flow Instability Under Compressive Loading During Shear Spinning Process

Journal of Engineering for Industry ◽

10.1115/1.3185791 ◽

1982 ◽

Vol 104 (1) ◽

pp. 17-22 ◽

Cited By ~ 45

Author(s):

Micha Gur ◽

Jehuda Tirosh

Keyword(s):

Flow Instability ◽

Compressive Loading ◽

Plastic Instability ◽

External Condition ◽

Tube Spinning ◽

Upper Bound Analysis ◽

Spinning Process ◽

Sudden Appearance ◽

Shear Spinning ◽

Bound Analysis

The sudden appearance of a material bulge beneath the roller during tube spinning operation (referred to as “plastic instability”) is considered experimentally and examined quantitatively via an upper bound analysis. The phenomenon is explained by a sudden transfer of flow from one admissible mode to its competing mode when an external condition (or few conditions) is changed in a certain way to be discussed (e.g., increasing the roller angle of attack, increasing the initial tube thickness, etc.). As a by-product, the interrelation between the dominant variables of the process emerges. The associated formulation with its inherent idealizations enables one to mark the line between favorable and unfavorable working conditions of the spinning process. Experimental evidence demonstrates the utility of the proposed approach.

Download Full-text

Suspension Design Optimization of a Washing Machine: Part I — Modeling and Validation Results

19th Design Automation Conference: Volume 1 — Mechanical System Dynamics; Concurrent and Robust Design; Design for Assembly and Manufacture; Genetic Algorithms in Design and Structural Optimization ◽

10.1115/detc1993-0300 ◽

1993 ◽

Author(s):

O. S. Türkay ◽

A. K. Tuğcu ◽

I. T. Sümer ◽

B. Kiray

Keyword(s):

Design Optimization ◽

Experimental Validation ◽

Linear Time ◽

Optimization Method ◽

Companion Paper ◽

Simulation Software ◽

Horizontal Axis ◽

Washing Machine ◽

Rigid Body Dynamic ◽

Linear Time Invariant

Abstract The development of a non-linear time invariant rigid body dynamic model and the experimental validation of the suspension system of a horizontal-axis washing machine has been discussed in previous works by the authors. In this paper (Part I), modeling and experimental validation of a different suspension configuration of a test washing machine is assessed. The simulation model predicts the transient and steady-state vertical and horizontal amplitudes within maximum errors of 10% and 14%, respectively. The results are consistent with the results of the previous work. Thus, the simulation software code is verified for a generalized suspension design optimization of horizontal-axis washing machines. In a companion paper (Part II), various formulations are discussed to select an objective function for parametric suspension design optimization and a parametric grid optimization method is implemented to the test washing machine introduced in this paper.

Download Full-text

Optimization Method of Machining Center Multi-Joint Stiffness Based on Orthogonal Experiment and FEA

Materials Science Forum ◽

10.4028/www.scientific.net/msf.697-698.253 ◽

2011 ◽

Vol 697-698 ◽

pp. 253-257

Author(s):

Ming Nan Sun ◽

Guo Fu Yin ◽

Liang Mi

Keyword(s):

Machine Tool ◽

Dynamic Characteristics ◽

Discrete Optimization ◽

Orthogonal Experiment ◽

Joint Stiffness ◽

Optimization Method ◽

Mean Frequency ◽

Machining Center ◽

Orthogonal Optimization ◽

Significant Factors

Machine tool joint stiffness has important affects on the dynamic characteristics of the whole machine tool. It is a challenging task to optimize multi-joint stiffness of the overall structure. By discussing the distribution of stiffness of linear guides, ball screws, bolt joints and bearings, a discrete optimization method of multi-joint stiffness of a machining center was presented based on orthogonal experiment and FEA. Mean frequency formulation was adopted to define the index of orthogonal optimization. According to the principle of orthogonal experiment, optimization levels were found out, sequence of the factors on the index of the orthogonal experiment was listed and significant factors were determined. Results of this research proved the validity and feasibility of the discrete optimization method of multi-joint stiffness of the whole machine tool by combining orthogonal experiment and FEA.

Download Full-text

Experimental Validation of Mathematical Framework for Fast Switching Valves Used in Digital Hydraulic Machines

ASME/BATH 2015 Symposium on Fluid Power and Motion Control ◽

10.1115/fpmc2015-9612 ◽

2015 ◽

Cited By ~ 2

Author(s):

Christian Noergaard ◽

Daniel B. Roemer ◽

Michael M. Bech ◽

Torben O. Andersen

Keyword(s):

Experimental Validation ◽

Switching Time ◽

Optimization Method ◽

Input Power ◽

Mathematical Framework ◽

Hydraulic Motor ◽

Switching Valve ◽

Fast Switching ◽

Hydraulic Machines ◽

Series Of Experiments

A prototype of a fast switching valve designed for a digital hydraulic transmission has been manufactured and experimentally tested. The valve is an annular seat valve composed of a plunger connected with a direct electromagnetic moving coil actuator as the force producing element. Based on an elaborate optimization method the valve is designed to maximize the efficiency of a digital hydraulic motor targeted to a wind turbine transmission system. The optimisation method comprises a mathematical framework which predicts a valve switching time of approximately 1 ms with a peak actuator input power of 10 kW during switching (mean of approximately 250 W) and a pressure loss below 0.5 bar at 600 l/min. The main goal of this article is validate parts of the mathematical framework based on a series of experiments. Furthermore, this article aims to document the experience gained from the experimental work and to study and assess a moving coil actuators suitability for the application.

Download Full-text