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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Frequency Optimization of Vibratory Rollers and Plates for Compaction of Granular Soil

Wersäll, Carl January 2016 (has links)
Vibratory rollers are commonly used for compaction of embankments and landfills. This task is time consuming and constitutes a significant part of most large construction and infrastructure projects. By improving the compaction efficiency, the construction industry would reduce costs and environmental impact. This research project studies the influence of the vibration frequency of the drum, which is normally a fixed roller property, and whether resonance can be utilized to improve the compaction efficiency. The influence of frequency on roller compaction has not before been studied but the concept of resonance compaction has previously been applied successfully in deep compaction of fills and natural deposits. In order to examine the influence of vibration frequency on the compaction of granular soil, small-scale compaction tests of sand were conducted under varying conditions with a vertically oscillating plate. Subsequently, full-scale tests were conducted using a vibratory soil compaction roller and a test bed of crushed gravel. The results showed that resonance can be utilized in soil compaction by vibratory rollers and plates and that the optimum compaction frequency from an energy perspective is at, or slightly above, the coupled compactor-soil resonant frequency. Since rollers operate far above resonance, the compaction frequency can be significantly reduced, resulting in a considerable reduction in fuel consumption, environmental impact and machine wear. The thesis also presents an iterative equivalent-linear method to calculate the frequency response of a vibrating foundation, such as a compacting plate or the drum of a roller. The method seems promising for predicting the resonant frequency of the roller-soil system and can be used to determine the optimum compaction frequency without site- and roller-specific measurements. / <p>QC 20160613</p>
2

Design ručně vedeného vibračního válce / Design of hand operated vibratory roller

Pažitný, Miroslav January 2018 (has links)
Main subject of this diploma thesis is design proposal of walk-behind vibratory roller which is a part of the light compaction technology. The proposal brings different design solution from existing products in the current market and it is aimed on the ergonomics and machine handling.
3

Inteligentní řídící metody v automatizaci procesů řízení stavebních strojů / Intelligent Control Methods in Automation of Process of Construction Machines Control

Vaverka, Michal January 2010 (has links)
This work deals with the possibility of use of intelligent methods in construction machines control. These methods are based on GPS in combination with using laser and ultrasonic technology. There is in detail described especially control by robotic total station and 3D control, which includes digital model of construction site. The new trends of control are especially applied on the vibratory rollers. There are taken into consideration: achievement of sufficient degree of compaction on the basis of on-line information about conditions of subsoil.
4

Analýza vibračního válce s novým typem kinematiky řízení / Analysis of vibratory roller with new type of steering kinematics

Votroubek, Jan January 2011 (has links)
Diploma thesis includes design of bearings of steering joints of tandem vibratory pivot-steering roller Ammann AV 95-2, design of bearings of steering joints of tandem vibratory with new type of steering kinematics and calculation and comparison of contact pressures between drum and soil for different angles of turn of front and rear drum for different types of tandem vibratory rollers. Comparison of contact pressures is realised for pivot steering roller AV 95-2, articulated tandem roller AV 80 X, articulated tandem roller with modified configuration of steering-joints and tandem roller with new type of steering kinematics.
5

Inteligentní řídící metody v automatizaci procesů řízení stavebních strojů / Intelligent Control Methods in Automation of Process of Construction Machines Control

Vaverka, Michal January 2010 (has links)
This work deals with the possibility of use of intelligent methods in construction machines control. These methods are based on GPS in combination with using laser and ultrasonic technology. There is in detail described especially control by robotic total station and 3D control, which includes digital model of construction site. The new trends of control are especially applied on the vibratory rollers. There are taken into consideration: achievement of sufficient degree of compaction on the basis of on-line information about conditions of subsoil.
6

Návrh hydraulického okruhu pojezdu vibračního válce ASC 110 / Design of the hydraulic circuit of the ASC 110 vibratory roller drive

Novák, Martin January 2019 (has links)
This thesis presents a proposal of newly designed concept for travel hydraulic circuit of vibratory single drum roller ASC 110. The maximum machine gradeability was chosen as the main parameter for hydraulic circuit proposal. After selecting the new hydraulic travel concept, suitable hydraulic components have been selected. Length and local losses for two different machine speeds were calculated for sufficient hydraulic circuit design. Hydraulic losses have also been calculated for use in different climatic conditions. A new machine cooling concept has also been proposed. Heating and cooling curves of hydraulic circuit were calculated. For the purpose of comparing gradeability and energy balance of the newly designed travel concept compared to the existing one currently in mass production, both machines were fitted with measuring points. On both machines were measured for example, pressure, flow and temperature in each hydraulic circuit branch and others. From the time dependencies of the above-mentioned parameters it was possible to determine the energy efficiency of the newly designed concept. To assess the maximum gradeability, the slope of the hill was measured. Comparing the two machines, it has been found that the two hydraulic circuit solution has significantly improved traction properties in demanding machine applications, especially when driving uphill and downhill. This concept also affects less fuel consumption and places less demand on the hydraulic oil cooler due to its energy efficiency.

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