scholarly journals A Load Identification Application Technology Based on Regularization Method and Finite Element Modified Model

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Bingrong Miao ◽  
Feng Zhou ◽  
Chuanying Jiang ◽  
Yaoxiang Luo ◽  
Hui Chen

An improved load identification technology of a beam based on different regularization methods and model modifying methods is presented in an attempt to minimize the estimation error at several periodic loads. A hybrid model is developed to simulate such ill-posed problem interactions under different noise levels. The finite element model is modified with the different optimization algorithms to obtain the equivalent constraint condition. Experimental verification is also carried out to obtain correct modes and frequencies by considered vibration response and different boundary conditions. The measured results demonstrate the good agreement with the identification results. The results are shown that the improved method not only has more adaptive range and higher identification accuracy but also has effective identification ability for loads under different noise levels.

2021 ◽  
Author(s):  
Sandeep Dhar

The trajectory of an angular particle as it cuts a ductile target is, in general, complicated because of its dependence not only on particle shape, but also on particle orientation at the initial instant of impact. This orientation dependence has also made experimental measurement of impact parameters of single angular particles very difficult, resulting in a relatively small amount of available experimental data in the literature. The current work is focused on obtaining measurements of particle kinematics for comparison to rigid plastic model developed by Papini and Spelt. Fundamental mechanisms of material removal are identified, and measurements of rebound parameters and corresponding crater dimensions of single hardened steel particles launched against flat aluminium alloy targets are presented. Also a 2-D finite element model is developed and a dynamic analysis is performed to predict the erosion mechanism. Overall, a good agreement was found among the experimental results, rigid-plastic model predictions and finite element model predictions.


Author(s):  
Chris Bassindale ◽  
Xin Wang ◽  
William R. Tyson ◽  
Su Xu

Abstract In this work, the cohesive zone model (CZM) was used to examine the transferability of the crack tip opening angle (CTOA) from small-scale to full-scale geometries. The pipe steel STPG370 was modeled. A drop-weight tear test (DWTT) model and pipe model were studied using the finite element code ABAQUS 2017x. The cohesive zone model was used to simulate crack propagation in 3D. The CZM parameters were calibrated based on matching the surface CTOA measured from a DWTT finite element model to the surface CTOA measured from the experimental DWTT specimen. The mid-thickness CTOA of the DWTT model was in good agreement with the experimental value determined from E3039 and the University of Tokyo group’s load-displacement data. The CZM parameters were then applied to the pipe model. The internal pressure distribution and decay during the pipe fracture process was modeled using the experimental data and implemented through a user-subroutine (VDLOAD). The mid-thickness CTOA from the DWTT model was similar to the mid-thickness CTOA from the pipe model. The average surface CTOA of the pipe model was in good agreement with the average experimental value. The results give confidence in the transferability of the CTOA between small-scale specimens and full-scale pipe.


2019 ◽  
Vol 271 ◽  
pp. 08008
Author(s):  
Mohsen Talebsafa ◽  
Stefan A. Romanoschi ◽  
Athanassios T. Papagiannakis ◽  
Constantin Popescu

A newly constructed pavement on US-287 near Mansfield, TX was instrumented with gauges installed at the bottom of the asphalt concrete base layer to measure the longitudinal and transverse strains developed under a test vehicle. The finite element program Abaqus was used to compute the strains at the location of the gauges; they were found in good agreement with the measured strains. The research showed that the strains under the steering axle were of similar magnitude as the strains under the rear tandem axle. The measured transverse strains were in general slightly bigger than the corresponding longitudinal strains, while the finite element model computed higher strains in the longitudinal direction. These findings suggest the need to account for the strain responses from the steering axle of trucks and to account for both the longitudinal and the transverse strains when computing the fatigue damage induced by trucks.


1998 ◽  
Vol 33 (4) ◽  
pp. 263-274 ◽  
Author(s):  
D J Smith ◽  
C G C Poussard ◽  
M J Pavier

Measurements of residual stresses in 6 mm thick aluminium alloy 2024 plates containing 4 per cent cold worked fastener are made using the Sachs method. The measurements are made on discs extracted from the plates. The measured tangential residual stress distribution adjacent to the hole edge are found to be affected by the disc diameter. The measured residual stresses are also in good agreement with averaged through-thickness predictions of residual stresses from an axisymmetric finite element (FE) model of the cold working process. A finite element analysis is also conducted to simulate disc extraction and then the Sachs method. The measured FE residual stresses from the Sachs simulation are found to be in good agreement with the averaged through-thickness predicted residual stresses. The Sachs simulation was not able to reproduce the detailed near-surface residual stresses found from the finite element model of the cold working process.


2007 ◽  
Vol 534-536 ◽  
pp. 1441-1444 ◽  
Author(s):  
Man Soon Yoon ◽  
Y.G. Choi ◽  
Soon Chul Ur

The electromechanical properties of a newly proposed 3-dimensional piezoelectric actuator have been investigated. Especially, the effects of 3-dimensional geometry on the maximum tip displacement were carefully investigated. As a result, it was found that the maximum strain of the 3-dimensional piezoelectric device was significantly enhanced up to 4.5 times higher than that of a disk shape device. This data was in good agreement with the finite element model analysis of strains and vibration modes. Moreover, the field -induced displacement stability of dome-shaped 3- dimensional piezoelectric actuator at various ac freguencies was superior to Rainbow actuator.


2014 ◽  
Vol 496-500 ◽  
pp. 601-604
Author(s):  
Jing Wang ◽  
Yong Wang ◽  
Ying Hua Liao

In this paper, the modal of motorcycle frame is analyzed by using the analytic method and experimental method. The results show that the dynamic properties of the finite element model are in good agreement with the experiment and the finite element model was reliable and accurate.


Author(s):  
Zahari Taha ◽  
Mohd Hasnun Arif Hassan

The soccer ball is one of the important pieces of equipment in the game of soccer. It undergoes various forms of impact during the game. In order to numerically investigate the occasions of ball impact such as soccer heading, a validated finite element model of a soccer ball is required. Therefore, a model was developed incorporating material properties obtained from literature. To ensure the accuracy of the model, it was validated against an established soccer ball model and experimental data of the coefficient of restitution, contact time, longitudinal deformation and reaction force. In addition, a parametric study of the mesh density was also performed to determine the optimal number of elements. The developed soccer ball model was found to be in a good agreement with the literature and experimental data. This suggests that, the soccer ball model is capable of replicating the impacts of interest. This article details the development of the model and the validation processes.


1991 ◽  
Vol 250 ◽  
Author(s):  
Ching-Yi Tsai ◽  
Seshu B. Desu

AbstractA two—dimensional finite element model was developed to study the step coverage of submicron trenches with arbitrary shape under chemical vapor deposition processes. Parameters that characterize the step coverage were found to be the surface Damkohler number, ratio of diffusion coefficients inside and outside of the trench, and aspect ratio of the trench geometry. Efforts were concentrated on studying the step coverage of SiO2 film deposited from SiH4/O2 precursors within rectangular shape trenches. The model predictions were found to be in good agreement with reported experimental results.


2018 ◽  
Vol 35 (3) ◽  
pp. 1279-1300
Author(s):  
Chenggang Pan ◽  
Zizheng Ding ◽  
Qingming Chang ◽  
Jialin Zhou

Purpose Surface defects are often present on the surface of continuous casting slabs and rolled products. A lot of surface defects of hot rolled products are inherited from initial defects on continuous casting slabs. This work aims to trace the original surface defect during the whole heavy rail rolling and avoid black line surface defect that appears on the surface of heavy rail finial product. Design/methodology/approach Artificial round hole-shaped surface defects on the surface of continuous casting slab during the hot rolling of 60 kg/m heavy rail are analyzed experimentally and by means of explicit dynamic finite element method (FEM) and modified model rebuilding method. Findings The calculated results of surface defect locations of heavy rail finial product are in good agreement with the experimental ones. It is shown that the explicit dynamic FEM and modified model rebuilding method can be used effectively to predict the flow behavior of surface defects in the hot rolling of 60 kg/m heavy rail. Originality/value The three-dimensional finite element model for whole heavy rail rolling is built using explicit dynamic code and modified model rebuilding method. Flow behavior of black lines is studied in the 60-kg/m heavy rail rolling. The simulation results of six typical points are in good agreement with the experimental results.


Author(s):  
Katie Leichliter ◽  
Bob Lounsbury ◽  
Judi Steciak ◽  
Ralph Budwig ◽  
Steve Beyerlein

Experimentally obtained temperatures of a heated coiled platinum wire in low Reynolds Number cross-flow were compared with a three-dimensional finite element (finite volume) model. The calculated average wire temperature was in good agreement with experimentally obtained values with deviations close to experimental uncertainty bounds at temperatures between 530K and 815K. The model predicted a temperature variation along each coil, with the lowest temperatures along the leading edges of the coil and the higher temperatures at the trailing edges. The rate of heat generated at the wire surface from catalytic reactions was found for the ignition of lean propane/oxygen/nitrogen mixtures. We studied the coiled catalytic wire as part of our efforts to ignite very lean homogeneous air-fuel mixtures in transportation engines under conditions approaching Homogeneous Charge Compression Ignition (HCCI).


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