The aim of this study is to perform the dynamic force analysis of a 3-degrees-of-freedom excavator during digging the soil and to simulate the motion on computer screen. Standard load calculations are done statically, therefore the effects of forces changing with time on the system cannot be observed. The dynamic analysis method used in the thesis is Recursive Newton &ndash / Euler Method and the numerical analysis method for simulation is 4th Order Runge &ndash / Kutta Method. After this study, the effects of sudden velocity changes / i.e, accelerational movements on construction machines, positions of bodies and dynamic forces on joints will be appointed and it will be possible to plan and control the motion.

The aim of this study is to develop a dynamic model of the loader system of a backhoe-loader. Rigid bodies and joints in the loader mechanism and loader hydraulic system components are modelled and analyzed in the same environment using the physical modelling toolboxes inside the commercially available simulation software, MATLAB/Simulink. Interaction between the bodies and response of the hydraulic system are obtained by co-operating the mechanical and hydraulic analyses. System variables such as pressure, flow and displacement are measured on a physical machine and then compared with the simulation results. Simulation results are consistent with the measurement results. The main result of this work is the ability to determine the dynamic loads on the joints and attachments of the backhoe-loader. In addition to that, prototyping time and costs can be highly reduced by implementing this model in the design process.

The aim of this study is to perform the dynamic force analysis of a 3-degrees-of-freedom excavator during digging the soil and to simulate the motion on computer screen. Standard load calculations are done statically, therefore the effects of forces changing with time on the system cannot be observed. The dynamic analysis method used in the thesis is Recursive Newton &ndash / Euler Method and the numerical analysis method for simulation is 4th Order Runge &ndash / Kutta Method. After this study, the effects of sudden velocity changes / i.e, accelerational movements on construction machines, positions of bodies and dynamic forces on joints will be appointed and it will be possible to plan and control the motion.

This study aims to develop a computer program to optimize the performance of loader mechanisms in backhoe-loaders. The complexity and the constraints imposed on the loader mechanism does not permit the use of classical optimization techniques used in the synthesis of mechanisms. Genetic algorithm is used to determine the values of the design parameters of the mechanism while satisfying the constraints and trying to maximize breakout forces that the machine can generate.

ABSTRACT DESIGN OF A DEMOLITION BOOM &Ccedil / etin, Bet&uuml / l M.S, Department of Mechanical Engineering Supervisor : Prof. Dr. Eres S&Ouml / YLEMEZ August 2007, 96 pages Excavators are used for many purposes. Some of these are digging, drilling, breaking and demolition. A demolition excavator boom consists of 3-piece boom which is different in form and construction from a 2-piece boom used in standard excavator. The aim of this thesis is to design a demolition boom for hydraulic excavator with operation weight of 30 ton. With this construction a higher reach is gained. Design of the demolition boom consists of three stages. Firstly the mechanism design is performed to determine the basic link dimensions. In the second step the structural shape of the boom is estimated to perform static stress analysis. The EXCEL program is chosen due to the ease of repetative calculations and applying the changes in structure parameters. The demolition boom is modeled by PRO-ENGINEER, and consequently the model is analyzed by using a Finite Element Analysis (FEA) in MSC.Marc-Mentat. According to the FEA results the model is revised. Keywords: Demolition Excavator, Mechanism Design, Structural design

This study concerns with acoustical analysis of exhaust mufflers for earth-moving machinery. The study arises from the fact that there is a need for further noise reduction emitted by earth-moving machinery produced by Hidromek Inc. in order to be on the safe side of the limits stated in European Noise Directive 2000/14/EC. The acoustical performance of the muffler is investigated both experimental and numerical means. A three-dimensional finite element method is performed to calculate the transmission loss. An experimental setup is also developed to measure the transmission loss. Chung-Blaser, two-source and two-load methods are applied to measure the transmission loss of single expansion chamber with extended inlet/outlet. The experimental setup is verified by comparing the test results obtained by two-load method with one-dimensional analytical solution obtained by transfer matrix method. Transmission loss of the muffler of interest, calculated by finite element method is compared with the experimental results. Sound power level of earth-moving machinery and insertion loss of the muffler is measured to investigate the acoustical performance of the muffler. These results can then be served as guidance for the acoustical design of a muffler.

This thesis is performed to evaluate the design consideration and performance characteristics of a surge tank for a diaphragm pump operation and to evaluate the proper volume and inlet area of surge tank in order to reduce the pulsations of the discharge pressure. An experimental set up is constructed for a three diaphragm positive displacement pump and the experiments are conducted afterwards. The surge tanks having different volumes and the surge tank inlet area configurations are tested in order to achieve the minimum peak to peak pulsations. Experiments showed that among the different sizes of the surge tanks, the minimum peak to peak pulsations are achieved with the largest volume which is the original surge tank of the test pump used by the pump manufacturer. This result is supported by the literature which states that with greater surge tank size the magnitude of pulsations can be diminished more. Regarding the surge tank inlet area design / among the eight different adaptors a proper inlet area value is concluded having the minimum peak to peak pulsations also smaller than the original configuration.

In this thesis study, a valveless hydraulic servo system controlled by two pumps is investigated and its performance characteristics are compared with a conventional valve controlled system both experimentally and analytically. The two control techniques are applied on the position control of a single rod linear actuator. In the valve controlled system, the flow rate through the actuator is regulated with a servovalve / whereas in the pump controlled system, two variable speed pumps driven by servomotors regulate the flow rate according to the needs of the system, thus eliminating the valve losses. To understand the dynamic behaviors of two systems, the order of the differential equations defining the system dynamics of the both systems are reduced by using the fact that the dynamic pressure changes in the hydraulic cylinder chambers become linearly dependent on leakage coefficients and cylinder chamber volumes above and below some prescribed cut off frequencies. Thus the open loop speed response of the pump controlled and valve controlled systems are defined by v second order transfer functions. The two systems are modeled in MATLAB Simulink environment and the assumptions are validated. For the position control of the single rod hydraulic actuator, a linear state feedback control scheme is applied. Its state feedback gains are determined by using the linear and linearized reduced order dynamic system equations. A linear Kalman filter for pump controlled system and an unscented Kalman filter for valve controlled system are designed for estimation and filtering purposes. The dynamic performances of both systems are investigated on an experimental test set up developed by conducting open loop and closed loop frequency response and step response tests. MATLAB Real Time Windows Target (RTWT) module is used in the tests for application purposes.