Journal of Mechanical and Energy Engineering

X-ray diffraction and thermo gravimetric analysis of surface modified areca sheath fibre epoxy composites

2023-03-23T09:20:27+01:00

Focus of the current study is to shed more light on thermal behaviour of composites made up of areca sheath fibres. The XRD analysis revealed that crystallinity index and crystallinity percentage increased with different treatments, as it leads to better interaction of fibre and resin. The crystallinity percentage of alkali treated fibre and benzoyl peroxide treated fibre increased by 5.87 and 8.44% respectively compared to untreated fibre. This was further evident in thermo studies which proved better thermal stability in benzoyl peroxide treated fibre composite.

Sequential treatment process in a rotary container polishing machine with periodic workpiece location changes in working abrasives areas

2023-03-23T09:20:27+01:00

This paper presents the process of a 3-step machining process involving pre-treatment, smoothing and polishing, placing the workpiece in different energy levels of the working load in a rotary-cascade container smoother, by moving it towards the radial direction of the working chamber of the smoother. Studies show the ability to control the course of pre-treatment, smoothing and finishing intensity, both in terms of process parameters and treatment time. Such a structure of the machining process, it also allows you to influence the structure geometry of the machined surfaces in successive stages of machining, and consequently on the final quality. The proposed organization and structure of the process allows for the creation of a new one surface treatment strategy.

Finite element analysis on prosthetic leg under different loads and flexion angles for medical applications

2022-10-06T13:50:17+02:00

Prosthetic legs (PL) are mainly used to perform leg amputations more easily. The design and performance of these legs mainly depend on the material selection and manufacturing methods. In the present study, alternative materials are considered for PL such as Al alloy, Ti alloy, Uni directional Carbon fiber epoxy (UDCFE), and combined composite material (CF, UDCFE and Ti alloy) to perform static and fatigue analysis . Static analysis was performed under four different load conditions 60 kg,70 kg, 80 Kg and 90 kg. Fatigue analysis was done under low cycle fatigue conditions. Theoretical calculations are evaluated at various inclinations of the foot 10°, 20°, and 30° with the ground. The results obtained theoretically are compared with Ansys results. The best material which gives the lesser value of deformation and lower damage factor is selected for the design. Further, experimental studies were suggested based on the results obtained from this work.

Effect of parameters of the stereolithography process on the part quality

2023-03-14T10:49:59+01:00

This paper investigates the effect of additive manufacturing parameters on the manufacturing quality of selected gear mechanism components. Three input variables, and two output variables were determined. The result was the determination of the most optimal combination of key parameters and the determination of regression equations. The concept of manufacturing objects of a very complex shape, by any person, under various conditions through the use of a low-cost device became the basis for this thesis topic. Curing time, layer thickness, and lift speed are among the basic parameters, with a large range of manipulation. A hypothesis was formulated that these three parameters are crucial to produce a part with the smallest possible deviations from the computer model. A handheld scanner was used to scan the samples and compare them with the CAD model. Based on the study, optimal parameters for layer thickness, curing time and lift speed were proposed.

Structural design of a boom mounting of a mast type jib crane for handling sludge pumps

2023-01-12T08:42:40+01:00

The paper is a continuation of the issue of the technical solution of a mast type jib crane for handling sludge pumps. It serves for the use in the building no. 900, block V2, of the nuclear power plant Jaslovské Bohunice. It is an optimization of the original, in-service damaged handling device with manual control of lift and rotation. It was found that the lifting force permanently falls within the recommended range of 120 to 160 N for convenient operation by a single worker. The problem of pulling out the sludge pumps ingeniously provided the opportunities to further design changes on the original design. The solution offered was to scrap the original design of the carrier inserted into the support and replace it with a fixed mast on which the boom would rotate. Accordingly, it would potentially be feasible to increase the load capacity of the jib crane, and thus the issue of the sludge pumps attached to the tank bottom would be solved. Accordingly, it would potentially be feasible to increase the load capacity of the jib crane, and thus the issue of the sludge pumps attached to the tank bottom would be solved.

Effect of simulated axial residual stress and transverse residual stress in welded P92 pipe and plates including plasticity error

2022-10-06T13:50:17+02:00

The paper deals with the measurement of the residual stresses in P92 welded pipe using the blind hole drilling technique.The post weld heat treatment (PWHT) of P92 welded pipe was also conducted to study their effect on residual stresses .The P92 pipe weld joints were prepared using gas tungsten arc welding process. The residual stress measurement was carried out using the strain gauge rosette that was associated with the plastic deformation of material and stress concentration effect of multi-point cutting tool. The corrective formulation was developed for calculating the corrected value of residual stresses from the experimentally obtained strain value. The Strain gauge response was estimated experimentally using the tensile testing for the uniaxial loading while finite element analysis was performed for biaxial loading. Gas tungsten arc welds joint was prepared for conventional V-groove and narrow groove design.

Forward and inverse kinematics solution of a robotic manipulator using a multilayer feedforward neural network

2022-10-17T15:05:57+02:00

In this paper, a multilayer feedforward neural network (MLFFNN) is proposed for solving the problem of forward and inverse kinematics of the manipulator. For forward kinematics solution, two cases are presented. The first case is that one MLFFNN is designed and trained to find only the position of the robot end-effector. In the second case, another MLFFNN is designed and trained to find both the position and the orientation of the robot end-effector. Both MLFFNNs are designed considering the joints’ positions as the inputs. For inverse kinematics solution, a MLFFNN is designed and trained to find the joints’ positions considering the position and the orientation of the robot end-effector as the inputs. For training any of the proposed MLFFNNs, data are generated in MATLAB using two different cases. The first case is considering incremental motion of the robot joints, whereas the second case is considering a sinusoidal motion. This method is designed to be generalized to any DOF manipulator. For simplicity, it is applied using a 2-DOF planar robot. The results show that the approximation error between the desired and estimated output is very low and approximately zero. The MLFFNN is efficient to solve the forward and inverse kinematics problems.

Characteristics of stress distribution of a multi layered cylindrical pressure vessel

2023-01-19T11:54:32+01:00

The operation of a multilayer pressure vessel subjected to thermomechanical loads is very significant. The cylindrical pressure vessel is widely used in industrial engineering, for example, to hold a variety of different types of liquid. On thick-walled cylinders, various loading circumstances such as internal overpressure, external overpressure, heat, bending, twisting, and combinations of these load characteristics are applied. Researchers have developed a number of strategies for enhancing the strength of cylinders, including the use of multilayer cylinders and increasing the thickness of the walls. This paper presents the results of an analytical and numerical analysis of a three-layer cylinder. Abaqus FEA software is used to determine temperature, displacement, and stress distribution of multilayer cylinder considering the effect of centripetal and centrifugal heat flow. From the numerical analysis it is observed that centrifugal heat flux is more hazardous than centripetal heat flux for multilayered cylinder under thermo-mechanical loading.