This paper is concerned with the solution of some inverse elasticity problems practical significance to experimental mechanics. More specifically, boundary tractions and displacements in an elastically deformed two‐dimensional body are calculated using experimentally determined or specified strains at a finite number internal points body. A brief description what why they important given. The element method used regularization techniques solve deformation concern here. Some illustrated...

Energy management strategies for a power-split hydraulic hybrid wheel loader are studied in this paper. The differences between the powertrain and energy system on-road vehicles off-road first identified. Unlike where engine powers only drivetrain, both drivetrain working system. In non-hybrid loader, two subsystems interfere with each other since they share same shaft. By using powertrain, not allows optimal operation regenerative braking but also greatly reduces interference functions. An...

The bucket motion of a wheel loader during the loading process is investigated in this study. optimal trajectory can be obtained by solving an control problem with performance criteria <bold xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">fill factor</b> , xmlns:xlink="http://www.w3.org/1999/xlink">fuel efficiency</b> and xmlns:xlink="http://www.w3.org/1999/xlink">operation cycle time</b> . A control-oriented model for operation developed. Based on...

This paper introduces an approach to study a valve's internal fluid dynamics. During operation, the flow causes forces on spool. These must be correctly balanced. Since these cannot measured, three-dimensional (3D) computational dynamic (CFD) modeling is needed. A case has been undertaken verify two-way pressure compensated control valve. vary during analysis transient. From initial zero spool position, goes through valve causing shift inside housing until stops at its final position. Forces...

Carbon nanotube (CNT) based optically transparent and electrically conductive thin films are fabricated on plastic substrates in this study. Single-walled carbon nanotubes (SWNTs) chemically treated with a mixture of concentrated sulfuric acid nitric before being dispersed aqueous surfactant-contained solutions. SWNT prepared from the stable solutions using wet coating techniques. The 100 nm thick film exhibits surface resistivity 6 kohms/square nanometer an average transmittance 88% visible...

This paper describes a shape control system for three roll bending process. The objective of this process is to impart desired curvature workpiece at each point along the length part. Since final part determined by which loaded and amount elastic springback, since latter strong function material properties workpiece, truly closed-loop controller must account these insure consistent performance. scheme presented here accomplishes measuring both shape, loading moment, effective beam rigidity...

This paper presents a novel method of capturing more energy from the wind using short-term storage in hydrostatic turbine. A transmission (HST) not only provides reliable operation but also enables management features like regeneration hydraulic accumulators. In this study, turbulence-induced transients occurring near rated power are exploited to extract wind. Wind characteristics analyzed develop models quantify losses due turbulence and potential gains storage. dynamic simulation model...

In this study we present a procedure for the design and implementation of control strategy to optimize energy use within light weight hydraulic hybrid passenger vehicle. The utilizes high pressure accumulator storage which has superior power density than conventional battery technology. This makes fluid attractive urban driving applications in there are frequent starts stops large startup demands. A dynamic model series powertrain is presented along with predictive based management strategy....

High power density, good controllability, and low cost are the most appealing characteristics that make hydraulic systems best choice for many applications. Current state-of-the-art variable displacement pumps show high efficiency at while they have poor efficiencies displacement. This paper proposes a novel alternating flow (AF) pump to: 1) eliminate metering losses by acting as high-bandwidth control; 2) achieve across wide range of operating conditions displacements; 3) allow multiple...

This paper explores the development of thin panels that can be controlled electronically so as to provide surfaces with desired reflection coefficients. Such used either perfect reflectors or absorbers. They also designed transmission blockers block propagation sound. The control system is based on use wave separation algorithms separate incident sound from reflected In order obtain a coefficient, appropriate levels. an acoustic reference for feedforward and has important property being...

An adaptive controller for a pressbrake has been designed, built, and tested. The measures force displacement during the early part of bend cycle to estimate workpiece parameters. These parameters are used in an elastic-plastic material model predict correct final punch position yield desired unloaded angle. A microcomputer is control Cincinnati CB90 hydraulic pressbrake. Data acquisition computation times short enough minimum flank angle 15 deg using standard forming rate 6.7 mm/s (16...

An improved adaptive pressbrake control algorithm is described. The problem to the punch reversal position of press so that final unloaded angle bend remains unchanged in presence material property and thickness variations sheets or plates being bent. Pressbrake algorithms use force-displacement data identify have shown promise. However, since previous controllers been based on an elastic-plastic model, parts overbent. In this paper, a controller elastic, power-law strain-hardening model...

The objective of this study is to develop an analytical approach calculate the relationship between axial curvature a bent tube and resulting deformation cross-section. model accounts for both geometrical material nonlinearities. An approximate expression in trigonometric form introduced displacement field, which reflects change wall thickness neutral axis shift during bending. total theory employed as constitutive relation. solution found using minimization energy principle. A better...

A novel method is described to estimate the material characteristics of a sheet being bent in pressbrake from punch force-displacement data. The simple enough be used for real time identification uncertain characteristics. This procedure can combined with model bending provide control pressbrake. setup eliminated, and final angle bends made insensitive property variations. machine controlled this manner integrated into an unmanned flexible metal manufacturing cell.

In this paper, a model predictive control (MPC) approach is presented for solving the energy management problem in parallel hydraulic hybrid vehicle. The vehicle uses variable displacement pump/motor combination to transfer between mechanical and domains high pressure accumulator storage. proposed controller observes gas brake pedal positions estimate desired wheel torque. It regulates engine throttle command, displacement, applied force track torque while optimizing powertrain efficiency....

Abstract This research presents a lumped parameter numerical model aimed at designing and optimizing an axial piston pump. For the first time, it has been shown that can accurately pump dynamics based on comparison with computational fluid dynamic (CFD) models experimental results. Since method is much more efficient than CFD, optimize design. Both steady-state behaviors have analyzed. The results compared data, showing good capacity in predicting performance, including pressure ripple....

In this paper, a three-dimensional (3D) computational fluid dynamics (CFD) methodology to improve the performance of hydraulic components will be shown, highlighting importance that study in mechanics field has for their optimization. As known, valve internal geometry influences proportional spool performance, axial flow forces, and spin effects on spool. Axial forces interact directly with position control direct actuating closed-loop valve, reducing its capability. The goal activity is...

The hydraulic power-split architecture, or the hydromechanical transmission, can exist in over 1000 configurations. Since a specific transmission configuration has unique kinematic characteristic, optimal for one application is different from configurations other applications. This study finds hybrid city bus. uses at least planetary gear set, process of finding suitable bus very time consuming, but this simplifies procedure by utilizing critical speed ratio ω crit , where missing link...

A three dimensional CFD analysis of a novel vane pump power split transmission is studied in this paper. The model was built using PumpLinx®, three-dimensional commercial code developed by Simerics Inc.® Mathers Hydraulics® double-acting with floating ring. By coupling the ring to an output shaft, becomes hydrostatic transmission. focus activity optimization analyzing internal fluid dynamics each part during operation and redesign. study result collaboration between University Minnesota...

This paper investigates power management strategies for hydraulic hybrid passenger vehicles. Parallel, series, and power-split architectures are modeled explored in the Matlab environment using variable efficiency pump/motor models. Results presented a rule-based strategy with ad hoc selection of engine on/off setpoints accumulator transmission gear shifting. The dynamic programming algorithm is then used to determine optimal trajectories engine/hydraulics splitting each over urban highway...