No description available.

The purpose with this thesis was to examine the cold rolling mill located at Högskolan Dalarna and to stabilize the rolling process, to achieve steady state. Experiments with cold rolling of an aluminium strip have given results for rolling force, friction, reduction, strip tension and strain hardening. Results show that steady state has been found for the experiments with roll force and strain hardening, and not been found for the experiments with friction and reduction. Results show that increased strip tension gives lower roll forces. The roll force equation of Stone shows comparable results with reality for dry contact with reductions up to 30 %, but starts being incomparable with higher reductions. The roll force equation of Stone shows a bit higher roll forces than reality gave, but was comparable within reductions from 13 to 50 %. Experiments have shown that the aluminium strip has gone through strain hardening. Experiments show how the set roll gap did not yield the desired thickness reduction, there for the elastic spring constant for the rolling mill was examined and determined to be 417 N / mm for the specific alloy band. The influence of tension strip for roll force was examined and Results confirm the theory about how the roll force is decreased by increasing tension strip. The work rolls started to slip against the alumina strip as high tension strip; 70 N/mm2, gave low roll force; < 15kN.

Rolling technology can control the thickness precisely. But it isn¡¦t available in width control. FEM software DEFORM 3D is adopted to simulate one stand of the hot finishing rolling process using carbon steel as sheet material. Stress, strain and width spread are discussed. Regression analysis is used to find an empirical equation for rolling load and width spread. Experiment and simulation of cold strip rolling using aluminum as sheet material are conducted,discussing the width spread and detail of width transformation in DEFORM 3D.From the comparisons between analytical and experimental width spread, the analytical model and prediction equation are validated.

A Rolling Dynamic Deflectometer (RDD) is a nondestructive testing device for determining continuous deflection profiles of pavements. Unlike discrete testing methods, the RDD performs continuous measurements. The ability to perform continuous measurements makes the RDD a powerful screening/evaluation tool for quickly characterizing large sections of pavement, with little danger of missing critical pavement features. RDD testing applications have involved pavement forensic investigations, delineations of areas to be repaired, selection of rehabilitation treatments, measurements of relative improvements due to the rehabilitation, and monitoring of changes with time (trafficking and environmental loading). However, the speed of RDD testing with the current rolling sensors is between 1 and 2 mph (1.6 to 3.2 km/hr). Improvements in testing speed and data analysis procedures would increase its usefulness in project-level studies as well as permit its used in some pavement network-level studies. A three-part study was carried out to further improve the RDD. The first part involved the development of speed-improved rolling sensors (referred as the third-generation rolling sensor). Key benefits of this new rolling sensor are: (1) increased testing speed up to 5 mph (8.0 km/hr), and (2) reduced level of rolling noise during RDD measurements. With this rolling sensor, the RDD can collect more deflection measurements at a speed of 3 to 5 mph (4.8 to 8.0 km/hr). Field trials using the first- and third-generation rolling sensors on both flexible and rigid pavements were performed to evaluate the performance of the third-generation rolling sensor. The second part of this study involved enhancements to the RDD data analysis procedure. An alternative data analysis method was developed for the third-generation rolling sensor. This new analysis method produces results at higher speeds that are comparable to the existing analysis method used for testing at 1 to 2 mph (1.6 to 3.2 km/hr). Key benefits of this analysis method that were not previously available are: (1) distance-based deflection profiles (report RDD deflections based on a selected distance interval), (2) improved-spatial resolution without sacrificing the filtering performance, and (3) analysis of the rolling noise characteristics and signal-to-noise and distortion ratios better characterize the deflection profiles and their accuracy. The third part of this study involved investigating the effects of parameters affecting RDD deflection measurements which include: (1) force level and operating frequency, (2) in-situ sensor calibration, (3) load-displacement curve, and (4) pavement temperature variations. These parameters need to be considered in testing and data analysis procedures of the RDD because small errors from these parameters can adversely influence calculations of the RDD deflections. Criteria are presented for selecting the best operating parameters for testing. / text

Thesis (M.S.)--Ohio University, March, 1994. / Title from PDF t.p.

During the cold reduction of steel sheet in a rolling mill, rolling oils are used for lubrication to provide the desired steel surface. Rolling oil formulations consist largely of mineral oils, glycerides and/or synthetic esters, fatty acids, emulsifiers and additives. These oils are generally used as 2-5% emulsions and will be subjected to high temperature and pressure during use. This results in chemical changes within the oil that can affect steel surface cleanliness after annealing. It is advantageous to have rolling oils that are stable but easily removed during annealing and leaving a minimal amount of residues. Thus in the field of rolling mill technology the surface quality of rolled product and stability of rolling oils are critical in the selection of lubricants. Additionally, production cost and environmental impact are also critical in the selection of lubricants. In this study, the performance of vegetable-based rolling oils was investigated by recording the FTIR spectra of the oils using Horizontal Attenuated Total Reflectance, an internal reflection accessory, before and after systematic heat treatment. Evidence was found that the vegetable-based oils degraded on heating and the spectroscopic analysis indicated that this was due to rearrangement of unsaturated components from a cis to a trans configuration. / Dissertation (MSc)--University of Pretoria, 2008. / Chemistry / unrestricted

The aim of this thesis is to design steel beams bending machine. In the introduction, is characterized by a bending machine and carried out research costs, including factory-produced manufacturers. Followed by a proposal of alternative solutions, evaluating them and selecting the most appropriate conception. The next section is described in detail the proposed model, including stress analysis of loaded parts. The thesis also examined the safety of a forming machine, prepared an analysis of possible defects and their consequences in the design. Finally, it created the design documentation on the proposed machine made pricing and maintenance described rolling machine.

This thesis investigates the design of a strip tension regulator by analytical techniques. The tension transfer function is non-linear and is derived for two conditions, first with only elastic deformation in the strip, and second with plastic flow in the strip resulting from reduction in the roll bite. The resulting transfer function consists of the one developed for elastic deformation with a degenerative feedback around it. This feedback is a result of reduction in the roll gap. The block diagram of the tension system reduces to a form containing two non-linear expressions. One is a second order equation describing the load and the other is third order equation describing the motor and the load effect on it. The motor is linearized by the addition of a high response armature current regulator. The tension regulator then reduces to a type I third order system. To compensate for the second order non-linearity in the regulator, a non-linear second order lead circuit is developed. This lead is modified continually as a function of strip velocity as well as coil radius and inertia. With the addition of this compensation, the tension regulator can be analyzed as a type I, first order system. / M.S.

published_or_final_version / Mechanical Engineering / Doctoral / Doctor of Philosophy

No description available.