Finite Element Analysis of Beams With Constrained Damping Treatment Modeled Via Fractional Derivatives

1997 ◽  
Vol 50 (11S) ◽  
pp. S216-S224 ◽  
Author(s):  
Luis E. Sua´rez ◽  
Arsalan Shokooh ◽  
Jose´ Arroyo

This paper presents a finite element formulation for the modeling of beams and frames with artificial damping provided by means of a constrained single layer of damping material. The behavior of the damping material is described using the fractional derivative model of viscoelasticity. In this model, the first order derivatives of the strains in the constitutive equations of the viscoelastic materials are replaced by derivatives of order α < 1. The finite element model developed is a one-dimensional beam element with three degrees of freedom per node. The dynamic response is calculated with a procedure involving a transformation of the original equations of motion to the state space and its decoupling with the eigenvectors of a special eigenvalue problem. The accuracy of the modal properties obtained with the beam model is compared with those calculated from a more elaborate plane stress finite element model. It was found that the proposed beam element provides very accurate results and with much lower computational costs than the 2-D model.

1996 ◽  
Vol 24 (4) ◽  
pp. 339-348 ◽  
Author(s):  
R. M. V. Pidaparti

Abstract A three-dimensional (3D) beam finite element model was developed to investigate the torsional stiffness of a twisted steel-reinforced cord-rubber belt structure. The present 3D beam element takes into account the coupled extension, bending, and twisting deformations characteristic of the complex behavior of cord-rubber composite structures. The extension-twisting coupling due to the twisted nature of the cords was also considered in the finite element model. The results of torsional stiffness obtained from the finite element analysis for twisted cords and the two-ply steel cord-rubber belt structure are compared to the experimental data and other alternate solutions available in the literature. The effects of cord orientation, anisotropy, and rubber core surrounding the twisted cords on the torsional stiffness properties are presented and discussed.


Author(s):  
Mohamed-Ouejdi Belarbi ◽  
Abdelhak Khechai ◽  
Aicha Bessaim ◽  
Mohammed-Sid-Ahmed Houari ◽  
Aman Garg ◽  
...  

In this paper, the bending behavior of functionally graded single-layered, symmetric and non-symmetric sandwich beams is investigated according to a new higher order shear deformation theory. Based on this theory, a novel parabolic shear deformation function is developed and applied to investigate the bending response of sandwich beams with homogeneous hardcore and softcore. The present theory provides an accurate parabolic distribution of transverse shear stress across the thickness and satisfies the zero traction boundary conditions on the top and bottom surfaces of the functionally graded sandwich beam without using any shear correction factors. The governing equations derived herein are solved by employing the finite element method using a two-node beam element, developed for this purpose. The material properties of functionally graded sandwich beams are graded through the thickness according to the power-law distribution. The predictive capability of the proposed finite element model is demonstrated through illustrative examples. Four types of beam support, i.e. simply-simply, clamped-free, clamped–clamped, and clamped-simply, are used to study how the beam deflection and both axial and transverse shear stresses are affected by the variation of volume fraction index and beam length-to-height ratio. Results of the numerical analysis have been reported and compared with those available in the open literature to evaluate the accuracy and robustness of the proposed finite element model. The comparisons with other higher order shear deformation theories verify that the proposed beam element is accurate, presents fast rate of convergence to the reference results and it is also valid for both thin and thick functionally graded sandwich beams. Further, some new results are reported in the current study, which will serve as a benchmark for future research.


Author(s):  
Luiz T. Souza ◽  
David W. Murray

The paper presents results for finite element analysis of full-sized girth-welded specimens of line pipe and compares these results with the behavior exhibited by test specimens subjected to constant axial force, internal pressure and monotonically increasing curvatures. Recommendations for the ‘best’ type of analytical finite element model are given. Comparisons between the behavior predicted analytically and the observed behavior of the experimental test specimens are made. The mechanism of wrinkling is explained and the evolution of the deformed configurations for different wrinkling modes is examined. It is concluded that the analytical tools now available are sufficiently reliable to predict the behavior of pipe in a manner that was not previously possible and that this should create a new era for the design and assessment of pipelines if the technology is properly exploited by industry.


2021 ◽  
Author(s):  
Oguz DOGAN ◽  
Celalettin YUCE ◽  
Fatih KARPAT

Abstract Today, gear designs with asymmetric tooth profiles offer essential solutions in reducing tooth root stresses of gears. Although numerical, analytical, and experimental studies are carried out to calculate the bending stresses in gears with asymmetric tooth profiles a standard or a simplified equation or empirical statement has not been encountered in the literature. In this study, a novel bending stress calculation procedure for gears with asymmetric tooth profiles is developed using both the DIN3990 standard and the finite element method. The bending stresses of gears with symmetrical profile were determined by the developed finite element model and was verified by comparing the results with the DIN 3990 standard. Using the verified finite element model, by changing the drive side pressure angle between 20° and 30° and the number of teeth between 18 and 100, 66 different cases were examined and the bending stresses in gears with asymmetric profile were determined. As a result of the analysis, a new asymmetric factor was derived. By adding the obtained asymmetric factor to the DIN 3390 formula, a new equation has been derived to be used in tooth bending stresses of gears with asymmetric profile. Thanks to this equation, designers will be able to calculate tooth bending stresses with high precision in gears with asymmetric tooth profile without the need for finite element analysis.


2014 ◽  
Vol 663 ◽  
pp. 668-674
Author(s):  
Azman Senin ◽  
Zulkifli Mohd Nopiah ◽  
Muhammad Jamhuri Jamaludin ◽  
Ahmad Zakaria

The Finite-Element Analysis (FEA) is a prediction methodology that facilitates product designers produced the part design with manufacturing focused. With the similar advantages, manufacturing engineers are capable of build the first actual car model from the new production Draw Die. This approach has eliminated the requirement to manufacture the prototype model from soft tool parts and soft tool press die. However, the prediction accuracy of FEA is a major topic of research work in automotive sector's practitioners and academia as current accuracy level is anticipated at 60%. The objective of works is to assess the prediction accuracy on deformation results from mass production stamped parts. The Finite-element model is developed from the CAD data of the production tools. Subsequently, finite-element model for production tools is discretized with shell elements to avoid computation errors in the simulation process. The sheet blank material with 1.5 mm and 2.0 mm thickness is discredited by shell (2D modeling) and solid elements (3D modeling) respectively. The input parameters for the simulation model for both elements are attained from the actual setup at Press Machine and Production Tool. The analysis of deformation and plastic strain are performed for various setup parameters. Finally, the deformation characteristic such as Forming Limit Diagram (FLD) and thinning are compared for all simulated models.


2013 ◽  
Vol 774-776 ◽  
pp. 25-29
Author(s):  
Cong Fang Hu ◽  
Yuan Qiang Tan

Based on the tandem sealing structure at the end of the shaft,a finite element model of rubber O-rings has been established and the sealing performance of rubber O-ring has been analyzed. There is an un-uniform compression among these O-rings which lead to the sealing failure. Under different friction factors, several groups of the rubber O-rings have been analyzed, finding that the friction factor is the reason of un-uniform compression. The effect of different average compression rate has been investigated, which has been integrated in the sealing criteria for the tandem O-rings, providing a reference for the optimization of tandem sealing structure at the end of the shaft. According to the sealing criteria for a single O-ring, the sealing criteria for the tandem O-rings is built.


2014 ◽  
Vol 635-637 ◽  
pp. 507-510
Author(s):  
Dong Peng Du ◽  
Zhe Wu ◽  
Juan Xing ◽  
Xiao Yan Gong ◽  
Xiang Wen Miu ◽  
...  

When strong exercise on human being body, respectively, under knees 30°, 60°,90°, using PRO/E5.0 software to establish the transverse patella fracture and anti-shearing force patella claws 3D models, then the two structure models were assembled and imported into ABAQUS10.1 software to establish the finite element model of patellar fracture fixed within patella claw, and analyzed the mechanical performance in perforce finite element model. Under the same boundary conditions, the maximum displacement and deformation of each components were different at every flexion angle. Compared with anti-shearing force patella claw and AO tensile force girdle, the patella claw with stronger resistance to tension and anti-shearing force was more stable. Deformation and displacement of patella claw in accordance with biomechanical research result that is needed by clinical. Its stability will satisfy clinical requirements for functional exercise.


2014 ◽  
Vol 945-949 ◽  
pp. 1143-1149
Author(s):  
Hai Xia Sun ◽  
Hua Kai Wei ◽  
Xiao Fang Zhao ◽  
Jia Rui Qi

The finite element model of the concrete mixing truck’s frame is builded by using shell as basic element, and the process of building the finite element model of the balance suspension is introduced in detail. Based on this, frame’s stress on five types of typical operating conditions are calculated by using the finite element analysis software, NASTRAN, and results can show the dangerous position and the maximum stress position on the frame. The analysis result on structural strength can provide the basis for further improving the frame structure.


2013 ◽  
Vol 284-287 ◽  
pp. 1831-1835
Author(s):  
Wei Hsin Gau ◽  
Kun Nan Chen ◽  
Yunn Lin Hwang

In this paper, two experimental techniques, Electronic Speckle Pattern Interferometry and Stroboscopic Interferometry, and two different finite element analysis packages are used to measure or to analyze the frequencies and mode shapes of a micromachined, cross-shaped torsion structure. Four sets of modal data are compared and shown having a significant discrepancy in their frequency values, although their mode shapes are quite consistent. Inconsistency in the frequency results due to erroneous inputs of geometrical and material parameters to the finite element analysis can be salvaged by applying the finite element model updating procedure. Two updating cases show that the optimization sequences converge quickly and significant improvements in frequency prediction are achieved. With the inclusion of the thickness parameter, the second case yields a maximum of under 0.4% in frequency difference, and all parameters attain more reliable updated values.


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