Design and analysis of biomimetics based excavator bucket and tooth

Within the scope of this paper, various bucket tooth designs and a biomimetic bucket design were created in order to produce a solution on digging efficiency which is one of the general problems of construction machines. These designs were inspired by giant anteater and American badger front claws. The inspiration aspect was diversified by integrating the paw and claw curves of the giant anteater and by bringing American badger claws into the design in different ways. Furhermore, the designed biomimetic bucket alternatives were compared between each other and the standard bucket equipment used in the market by making a computer aided static analysis. The compared criteria were the equivalent stress and total deformation formed on the bucket itself, the excavation equipment and the excavated soil. According to the analysis results, when the bucket tooth named P2 is mounted to the standard bucket, it has 42% lower Von-Mises stress on than standard bucket tooth. Additionally, it is exposed 4,7% less total deformation than standard tooth. Also, in terms of maximum Von-Mises stress formed on the soil model, P2 causes 17,5% greater stress than the standard bucket tooth.

Analysis of the Effects of Failure of a Gas Pipeline Caused by a Mechanical Damage

Natural gas continues to be one of the basic energy sources used as fuel in the power sector, in industries and in households. The potential and attractiveness of this fuel is gaining special significance in the current energy transitions from coal-based power engineering to power generation based on renewable energy sources. Natural gas is supplied to consumers mainly through a network of pipelines, which ensures a relatively high reliability of the supply. Still, failures occur due to the corrosion of pipeline walls, material defects or human errors, which can result in uncontrolled release of gas. The released gas can trigger dangerous phenomena, such as fires and explosions. This paper presents an analysis of the causes and effects of damage to a medium-pressure pipeline caused by earthworks carried out within an area where a pipeline is located. Holes in the pipeline due to the impact of an excavator bucket are analysed. The impact of the excavator bucket may cause a rupture equal to 50% of the pipeline’s cross-sectional area. Hazard zones related to fires and explosions due to the released natural gas are presented. For the analysed pipeline with a diameter of 0.5 m and a gas pressure of 5 MPa, the range of hazard zones arising due to pipeline damage caused by an excavator bucket can reach about 200 m.

EXCAVATOR WORKING EQUIPMENT FOR ISLANDS OF PIPELINE REPAIR

Work objective. Modernization of the excavator's working equipment design intended for islands of pipeline repair together with confirmation of its operability by checking the machine for stability, carrying out the necessary calculations of the hydraulic system. Methods. The main idea is in accessorizing the main working equipment of the excavator with a structure consisting of three teeth, which is in a body with an excavator bucket form a pickup mechanism. To confirm the operability of the proposed design, theoretical studies have been carried out aimed at determining the stability of the machine for the most dangerous design operating positions, and permissible pipe sizes have been established so that working with these sizes provides the stability of the machine. Results. A variant of improving the design of the excavator working equipment of the third size group has been developed. The equipment is intended for carrying out random repair of the pipeline by the excavator without involving other road construction equipment (for example, a pipelaying crane). The proposed design of the working body allows speeding pipeline repair by reducing the time spent on changing or relocating the equipment, which as a result reduces the cost of repair work. Conclusions. Calculations of the excavator hydraulic system have been carried out. In addition, as a result of theoretical studies, calculated dependences have been obtained, which made it possible to establish the stability coefficient of the excavator of the third size group when working with upgraded equipment and the pipeline diameter in the range of 720 ...1420 mm. As a result of the research, it was found that the proposed equipment is effective for carrying out random repairs of pipelines with diameters of 720, 1020 and 1220 mm. The stability of the machine in the most dangerous positions is being carried out. The calculation shows that when the excavator does demolition works of a pipeline with a diameter of 1420 mm, there is a danger of overturning the machine due to a decrease in the Ku coefficient below the permissible value.

Evaluating the impact of excavator bucket capacity on the output of a haul truck in different variants of their positioning

When studying the influence of excavator bucket capacity on haul truck loading time, it is necessary to assess the technical and economic performance of the complex. If the cost of the machine shift of the complex will not cover the increase in productivity, then it is inexpedient to use this complex. This issue requires further, more detailed study and performance of detailed technical and economic analysis. Also, it is necessary to consider classical recommendations about ratio of excavator bucket capacity and haul truck body. It should be noted that at present, there is a significant divergence in the size range of excavators: powerful, with a large capacity bucket, rope shovels are used for mining the coalless zone; small maneuverable hydraulic shovels – for mining the coal-bearing zone. In this paper, we will try to combine the first and the second: consider hydraulic excavators with maximum bucket capacity, which is reasonable to use when mining overburden. In addition, a detailed study of the options of mutual arrangement of excavator and haul truck has not been performed until recently, this work is intended to fill this gap.