Papers by Keyword: Finite Element

Abstract: A finite element model was developed in this research to investigate the impact of defects on the mechanical properties of a 3D-printed composite sandwich panel that could occur during the layer alteration period between the dissimilar materials, affecting the interfacial strength between the layers and causing the 3D-printed panel to fail. Numerous parameters, such as interfacial position, size, material properties, and location of defects along the panel, have been examined that might affect the failure mechanism. This finite element study adopted linear elastic behavior by utilizing ANSYS simulation program. The outcomes showed that the midsection of the composite is under a lot of stress, and as we approach the edges of the composite, the tension concentration falls outward until it reaches zero. In the intact scenario, the deformation was zero at either end of the panel and highest in the composite middle. The shear stress was most significant in the center, and it decreased as we moved closer to the extremities of both sides, it gradually decreased until it was lowest there. The endpoints where we have support responses have significant maximum shear stresses, which could degrade the material overall mechanical properties. This rise in the maximum principle stress at the end support could be due to the reaction of the fixed support, which tries to counteract the applied flexural load and raise the maximum principle stress.

Abstract: Computational methods become a necessity at places where the fields of testing as well as lab model testing poses problems or situations demanding large number of test results at low cost. The accuracy of the computational model can be adjusted by convergence study. The present study uses finite element method for finding static behaviour of sandwich plates having functionally graded core. Power law is employed for quantification of the material properties and zig-zag theory is utilized for the analysis. Hamilton’s theorem is exploited for deriving the equation which is resolved by FEM by taking nine-node C-0 iso-parametric FE having 11 DOF/node. Aspect ratio, power law coefficient and skewness of plate are used as variables to study the bending response of the plate. Present results are found to be consistent with the published ones and new results are also presented.

Abstract: Footsteps are a foothold for motorbike riders and passengers; they also play a role in maintaining stability when driving. Footsteps must have a solid and lightweight material to support the load from the feet and body of the rider and passengers. In this study, the footstep with the material made from the waste drum brake shoe varied by reducing mass through the static structural simulation process and topology optimization process using Ansys Workbench to get optimal mass, total deformation, equivalent stress, maximum principal stress, and safety factor from each variation. The footstep geometry will be subjected to a load of 1000N and provided with the necessary support. Based on the data obtained during this study, the initial footstep geometry produces data in the form of total deformation (1.383 mm), equivalent stress (21.013 MPa), and safety factor (1.227). The 10% variation produces data in the form of total deformation (1.4368 mm), equivalent stress (20,564 MPa), ,and safety factor ( 1.2538). The 20% variation yields data in the form of total deformation (0.98037 mm), equivalent stress (18.111 MPa), maximum principal stress (18.41 MPa), and safety factor (yield strength: 1.4236,. At the same time, the 25% variation produces data in the form of total deformation (1.3058 mm), equivalent stress (22.27 MPa), and safety factor (1.1577).

Abstract: Orthopedic cement is an essential component of cemented Total Hip Replacements (THR). It must ensure three essential functions: very good implant-cement adhesion, good bone-implant load transfer, and good antibiotic transport. The main objective of the present work is to study the fracture behavior of orthopedic cement in total hip replacements. The analysis is performed using the submodel technique. Two cases are being considered. The first case involves ordinary cracks, while the second case involves cracks emanating from cavities in the cement of the THR acetabular part. The effects of crack position and implant orientation on the variation of stress intensity factors (SIF) in the three failure modes are discussed. It has also been shown that the circumferential positions of cracks present a major risk of loosening of the prosthesis, especially when the defect is aligned with its axis.

Abstract: The topological phononic crystal is composed of two topologically distinct structures. The topological phononic crystal resonant cavity based are proposed and the acoustic wave propagate characteristics are also presented. The topological cavity with defects will change the resonance frequency and quality factor is also discussed. The advantages of the topological cavity are the better quality factors and the concentrated sound pressure larger than general defect cavity.

Abstract: Due to the importance of the joists slab system as an excellent solution for increasing span demands in different building types, investigating its properties becomes essential for different researchers. The effects of numerous parameters on the structural behaviour of the joists slab system, whether it was a waffle, ripped, or composite sections were reviewed in this paper from past studies. This study aims to determine the most effective parameters for the joist's system loading capacity. The main conclusions were that the slab thickness and joist height were the critical parameters for increasing the load capacity and stiffness of the slab. Furthermore, a small opening in the slab was more efficient in reducing the punching shear effect than larger openings. While providing stiffening rips around the opening was more effective in rose load bearing and reducing deflection than strengthening by carbon fibre sheets.

Abstract: There is a need for railway systems and upgrade their infrastructure to meet the future growing demand. This would expand the railway network by planning new track routes to increase the efficiency of railway transportation by running behavior of high train speeds between urban cities. The track/ballast; sleepers; and subgrade foundation system are important superstructure parts that need to be upgraded and improved to withstand high train speeds. A numerical finite element technique significantly benefits in simulating the impact of the dynamic response and predicting the deformation and stress distribution in the railway ballasted system. A three-dimensional finite element program PLAXIS ver. (20) have been utilized in this research to analyze the track of complex behavior under train loading. The vertical displacement of 3.8 mm was obtained at the rail/wheel contact point and greater than at the ballast embankment by about (19%) and (37%) for the subgrade foundation. Also, the maximum value of vertical displacement corresponds with the movement path of the train load is reduced laterally as the distance from the track centerline increases. The maximum vertical acceleration of 15.2 m/s² was obtained at surface points under track loading and decreased gradually with increased depth below the ballast embankment layer to reach a minimum value of 1.2 m/s². The vertical deformation was 1.3 mm, 2 mm, and 3.9 mm for 40 km/hr, 50 km/hr, and 60 km/hr respectively, and increased rapidly to 15 mm for train velocity greater than 70 km/hr due to the significant increase in train vibration level at higher speed. A critical train speed of 70 km/hr was observed that promoted the level of vibration and magnified the area of influence.

Abstract: Conventional finite element (FE) modelling, which employed structured mesh, is unable to simulate local damage evolution at microstructure level. This paper aims to investigate the creep rupture and damage behaviour of Grade 92 steel under a creep environment using microstructural-type FE mesh. The idealised microstructures of the material were generated based on the Voronoi tessellation technique. Three notched bar specimens with different notch acuities were modelled in Abaqus v6.13 software and a ductility exhaustion based damage model was employed to estimate the damage state. The influence of the notch constraint on the ductility is accounted for in the simulation. It is found that the results obtained from the proposed technique are in good agreement with the experimental data. All the prediction points fall within the scatter band of +/- factor of 2. The damage was predicted to initiate at a distance offset from the notch tip. As the acuity increases, the damage initiation site shifts further away from the notch.

Abstract: This paper presents the simulation of beef freezing process by using ANSYS software. On the basis of simulation results, factors affecting the freezing time including air velocity and freezing temperature were determined. Within the air velocity range ω = (5÷15) m.s^-1, an increase in the velocity by ω=1 m.s^-1 led to a decrease in the freezing time by τ =(6,5÷2,0) %. When the freezing temperature was reduced by t_e = 1 K, the freezing time was reduced by τ = (3,2÷2,5) % in the freezing temperature range t_e = (–35÷–45) °C.

Abstract: The main shaft of shot blasting machine mainly uses cylindrical roller bearing as the supporting part. The influence of stress, strain and temperature on bearing damage was studied by thermal structural coupling analysis of the bearing through finite element simulation. The causes and main damage forms of bearing surface were verified by super depth of field observation and finite element analysis. It is found that there exists pyramidal strain in the contact area between inner and outer raceway and roller, and its distribution form is continuous point distribution. The stress concentration is mainly distributed in the contact area between the roller face and the retaining edge, and the roller temperature is more concentrated in the area near the end face. The maximum length and depth of spalling pit on racetrack surface were 572.2μm and 14.15μm respectively. The maximum width and depth of the scratches on the roller surface are 386.7μm and 10.7μm, and the damage degree of the roller surface is not uniform. The thermo-structural coupling analysis is used to simulate the running state of bearings, which is of guiding significance to analyze the failure forms of bearings and improve the service life of bearings.