scholarly journals A Theoretical Method for Structural Design and Analysis of Crankshafts

2015 ◽  
Vol 7 (3) ◽  
Author(s):  
Sergio Baragetti
Keyword(s):  
Finite Element ◽  
Theoretical Model ◽  
Structural Design ◽  
Finite Element Modelling ◽  
Theoretical Method ◽  
Simple Theoretical Model ◽  
Element Simulation ◽  
Strain Behaviour ◽  
Numerical Finite Element ◽  
Theoretical Procedure

The crankshaft is the crucial mechanical component in many machines and engines and its fatigue assessment is often very time consuming and expensive. The machine designer usually needs a simple theoretical model that would allow choosing the best material and the dimensions of the component in a quick and reliable way. The numerical finite element simulation of crankshafts should follow the first step of theoretical dimensioning with the aim of evaluating the stress-strain behaviour at the notched area to verify the component against fatigue failure. The development of an intermediate theoretical model would prove effective to reduce the time needed to reach a second approximation design of the crankshaft. The aim of this paper is to give the designer a theoretical procedure that allows determining the strain and stress state for verification of crankshafts. The model was developed in the case of crankshafts with two connecting rods and validated by means of numerical finite element modelling and analysis.

Simulation research on low frequency sound absorption of monostable metamaterials

2021 ◽  
Vol 263 (6) ◽  
pp. 648-652
Author(s):  
Tuo Xing ◽  
Xianhui Li ◽  
Xiaoling Gai ◽  
Zenong Cai ◽  
Xiwen Guan
Keyword(s):  
Magnetic Field ◽  
Finite Element ◽  
Theoretical Model ◽  
Finite Element Simulation ◽  
Sound Absorption ◽  
Magnetic Force ◽  
Low Frequency ◽  
Low Frequencies ◽  
Element Simulation ◽  
Simulation Results

The monostable acoustic metamaterial is realized by placing a flexible panel with a magnetic proof mass in a symmetric magnetic field. The theoretical model of monostable metamaterials has been proposed. The method of finite element simulation is used to verify the theoretical model. The magnetic force of the symmetrical magnetic field is simplified as the relationship between force and displacement, acting on the mass. The simulation results show that as the external magnetic force increases, the peak sound absorption shifts to low frequencies. The theoretical and finite element simulation results are in good agreement.

The sagittal curvature of the spine can be a leading cause of scoliosis in pediatric spine

2021 ◽  
Author(s):  
S Pasha
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Early Stage ◽  
Element Model ◽  
Sagittal Profile ◽  
Deformation Pattern ◽  
Element Simulation ◽  
Curve Deformation ◽  
Numerical Finite Element ◽  
Deformation Patterns

The etiology of the adolescent idiopathic scoliosis (AIS) remains unknown. Variations in the sagittal profile of the spine between the early stage scoliotic and non-scoliotic pediatric patients have been shown. However, no quantitative study has shown the link between the sagittal profile and 3D deformity of the spine. 126 right thoracic scoliosis with spinal and 3D reconstructions were included. A 2D finite element model was developed for each of the sagittal curve types without any deformity in the frontal or axial planes. Physiological loadings were determined from the literature and were applied in the finite element model. The 3D deformation patterns of the models were compared to the 3D spinal patterns of the AIS with the same sagittal type. A significant correlation was found between the 3D deformity of the scoliotic curves and the numerical finite element simulation of the corresponding sagittal profile as determined by pattern correlation, p<0.001. The sagittal curve deformation patterns corresponded to the spinal deformities in the patients with the same sagittal curvature. Finite element models of the spines, representing different sagittal types in 126 AIS patients showed that deformation pattern of the sagittal types changes as a function of the spine curvature and associates with the patterns of 3D spinal deformity in AIS patients with the same sagittal curves. This finding provided evidence that the sagittal curve of the spine can determine the deformity patterns in AIS.

Static Characteristics of Micro Disc Magneto Electric Generator – Simulation and Experiment

2013 ◽  
Vol 365-366 ◽  
pp. 356-359
Author(s):  
Lin Du ◽  
Geng Chen Shi ◽  
Jing Jing Zhao
Keyword(s):  
Finite Element ◽  
Structural Design ◽  
Experimental Result ◽  
Static Characteristics ◽  
Element Analysis ◽  
Electric Generator ◽  
Design And Optimization ◽  
Element Simulation ◽  
Simulation And Experiment ◽  
3D Software

Maxwell 3D software of finite-element analysis in electromagnetic fields is used to model and simulate the micro disc magneto electric generator. Distribution characteristics of magnetic induction are required and theoretical analysis and calculation is presented. Error between the simulation result and experimental result is about 6% which verify the rationality and accuracy of finite-element simulation. It can be used to guide the structural design and optimization of this type of generator.

scholarly journals Finite element modeling of nanoindentation on an elastic-plastic microsphere

2020 ◽  
Author(s):  
Jialian Chen ◽  
Hongzhou Li
Keyword(s):  
Finite Element ◽  
Mechanical Behavior ◽  
Computational Study ◽  
Theoretical Method ◽  
Finite Element Analyses ◽  
Structured Materials ◽  
Elastic Plastic ◽  
Element Simulation ◽  
Insight Into

Abstract The understanding of the mechanical indentation on a curved specimen (e.g., microspheres and microfibers) is of paramount importance in the characterization of curved micro-structured materials, but there has been no reliable theoretical method to evaluate the mechanical behavior of nanoindentation on a microsphere. This article reports a computational study on the instrumented nanoindentation of elastic-plastic microsphere materials via finite element simulation. The finite element analyses indicate that all loading curves are parabolic curves and the loading curve for different materials can be calculated from one single indentation. The results demonstrate that the Oliver-Pharr formula is unsuitable for calculating the elastic modulus of nanoindentation involving cured surfaces. The surface of the test specimen of a microsphere requires prepolishing to achieve accurate results of indentation on a micro-spherical material. This study provides new insight into the establishment of nanoindentation models that can effectively be used to simulate the mechanical behavior of a microsphere.

scholarly journals EFFECT OF FLAT AND HEMISPHERICALLY ENDED CYLINDER BIRD MODEL WITH FINITE ELEMENT MODELLING OF BIRD STRIKE

2019 ◽  
Vol 17 (1) ◽  
pp. 41
Author(s):  
Endah Yuniarti
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Finite Element Modelling ◽  
Model Simulation ◽  
Material Model ◽  
Stagnation Pressure ◽  
Bird Strike ◽  
Element Modelling ◽  
Element Simulation ◽  
Simulation Results

This research studies influence of bird model on impact pressures during bird strike, namely Hugoniot and Stagnation pressure through initial modelling by numerical simulations using finite element method. Finite element simulation of bird strike have primarily modelled the bird as either a flat or hemispherically ended cylinder. The geometry is simulated with different L/D ratio, 1.4, 1.6, 1.8 and 2.0. Elastic-plastic hydrodynamic material model is used in simulation. Bird model simulation are using lagrangian method and initial velocities are 100, 200 and 300 m/s. Simulation results of hemispherically ended cylinder bird models show variation of L/D ratio provide Hugoniot pressure 10-19 times higher than stagnation pressure in L/D = 1.4, 8-18 times in L/D = 1.6, 9-17 times in L/D = 1.8 and 4-16 times in L/D = 2. The Hugoniot pressure shows a lower value at an L/D ratio of 1.6 compared to other ratios and the Stagnation pressure is higher at L/D ratio 2. As for cylindrical bird model show variation of L/D ratio provide Hugoniot pressure 35-38 times higher than stagnation pressure in L/D = 1.4, 30-47 times in L/D = 1.6, 31-52 times in L/D = 1.8 and 28-48 times in L/D = 2. The Hugoniot pressure shows a lower value at an L/D ratio of 1.4 and 1.6 compared to other ratios and the Stagnation pressure is higher at L/D ratio 2.

Bio-Inspired Fast Actuation by Mechanical Instability of Thermoresponding Hydrogel Structures

2016 ◽  
Vol 83 (7) ◽  
Author(s):  
Xuxu Yang ◽  
Guorui Li ◽  
Tingyu Cheng ◽  
Qian Zhao ◽  
Chunxin Ma ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Finite Element ◽  
Control System ◽  
Structural Design ◽  
Multilayered Structure ◽  
Mechanical Instability ◽  
Triggering Mechanism ◽  
Element Simulation ◽  
Ca Alginate ◽  
Poly Acrylamide

Inspired by natural plants, thermoresponding hydrogel (TRH) structures have been designed to trigger mechanical instability with fast actuation. Tough Ca-alginate/poly(N-isopropylacrylamide) (PNIPAM) hydrogel has been synthesized by the hybrid of physically cross-linked alginate and covalently cross-linked PNIPAM. The tough Ca-alginate/PNIPAM hydrogel exhibits 30 kPa of elastic modulus, 280 J/m2 of fracture energies, and fivefold of uniaxial stretch. A multilayered structure made of (Ca-alginate/PNIPAM)/(Ca-alginate/poly (acrylamide)) hydrogels demonstrate fast actuation induced by mechanical instability. A finite-element simulation model is developed to investigate the deformation and to guide the structural design of the hydrogels. The instability-triggering mechanism can enhance the actuation performances of hydrogel structures in applications, such as drug delivery, microfluid control system, and soft biomimetic robotics.

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