Three-Dimensional Analysis of Continuously Reinforced Concrete Pavements

2000 ◽  
Vol 1730 (1) ◽  
pp. 43-52 ◽  
Author(s):  
Seong-Min Kim ◽  
Moon C. Won ◽  
B. Frank McCullough
Keyword(s):  
Reinforced Concrete ◽  
Three Dimensional ◽  
Drying Shrinkage ◽  
Nonlinear Effects ◽  
Element Model ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Transverse Steel ◽  
Three Dimensional Finite Element

Continuously reinforced concrete pavement (CRCP) performance depends primarily on early-age cracks that result from changes in temperature and drying shrinkage. Presented is the behavior of the CRCP due to the temperature change obtained by using a three-dimensional finite element model. The nonlinear effects of the bond-slip between concrete and steel and between concrete and base have been studied. Modeling for the curling effect and for the viscoelastic material characteristics also has been considered. The results from the two-dimensional and three-dimensional models have been compared to verify the possibility of using a two-dimensional model. From this study, it was found that crack width and concrete stress are dependent on the transverse steel arrangement near the edge (longitudinal joint), but they are almost independent in the interior of the slab. The tensile stress occurring at the top of the edge on the transverse steel location can be higher than that occurring at the top of the slab center. This represents the possibility of forming a transverse crack from the edge on the transverse steel location. The twodimensional model with the plane stress element gives results very close to those of the three-dimensional model, except near the edge.

Comparative two- and three-dimensional finite element modelling techniques for tibial fractures

2001 ◽  
Vol 215 (2) ◽  
pp. 255-258 ◽  
Author(s):  
S Mishra ◽  
T N Gardner
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Stress And Strain ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Principal Stresses ◽  
Two Dimensional Model ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Often the choice of a two-dimensional modelling approach over a three-dimensional approach is made on the basis of available resources, and not on task appropriateness. In the case of simulating the mechanical behaviour of irregular anatomical structures in biomedical engineering, the authenticity of two-dimensional model behaviour and the interpretation of model solutions is of particular concern since little comparable two-dimensional and three-dimensional data have been published. As part of a research programme, a comparison was made between two-dimensional and three-dimensional finite element models (FEMs) that examine the stress-strain environment of a clinical bone fracture and callus. In comparison with the three-dimensional model, the two-dimensional model substantially underestimated peak compressive principal stresses in the callus tissue and peak equivalent strains. This was a consequence of geometrical and structural asymmetry in a plane perpendicular to the two-dimensional model. However, the two-dimensional model predicted similar patterns of stress and strain distribution to the corresponding mid-longitudinal plane of the three-dimensional model, and underestimates of peak stress and strain were much reduced. This confirmed that despite the irregular geometry and structure of the subject, the two-dimensional model provided a valid mechanical simulation in the plane of the fracture that it represented.

scholarly journals An Efficient Dynamic Modeling Technique for a Central Tie Rod Rotor

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Jingze Liu ◽  
Qingguo Fei ◽  
Shaoqing Wu ◽  
Zhenhuan Tang ◽  
Sanfeng Liao ◽  
...  
Keyword(s):  
High Efficiency ◽  
Experimental Testing ◽  
Research Work ◽  
Three Dimensional ◽  
Element Model ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Mass Model ◽  
One Dimensional ◽  
Three Dimensional Finite Element

Compared with the three-dimensional rotor model for a central tie rod rotor, an equivalent one-dimensional model can greatly improve the computational efficiency in rotor dynamics analysis with a certain accuracy. However, little research work can be found on improving the modeling accuracy of one-dimensional models using experimental data. In this paper, a one-dimensional discrete mass model considering pretightening force is proposed for central tie rod rotors to achieve the purpose of both efficient and accurate modeling. Experimental testing and three-dimensional model analysis are used as reference and verification approaches. A sensitivity-based method is adopted to update the proposed one-dimensional model via minimizing the error in the critical speed comparing with the corresponding three-dimensional finite element model which has been verified by a modal test. Prediction of damped unbalanced response is conducted to show the practicality of the updated one-dimensional model. Results show that the method presented in this research work can be used to simulate a complex preloaded rotor system with high efficiency and accuracy.

Two-dimensional and three-dimensional finite element models of external thread rolling

2002 ◽  
Vol 216 (4) ◽  
pp. 507-517 ◽  
Author(s):  
J P Domblesky ◽  
F Feng
Keyword(s):  
Three Dimensional ◽  
Finite Element Models ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Dimensional Finite Element ◽  
Thread Rolling ◽  
Three Dimensional Finite Element ◽  
Strain Model ◽  
Plane Strain Model

In the present study, the DEFORM computer code was used to develop two-dimensional and three-dimensional finite element models for simulating external thread rolling. To simulate rolling in two dimensions, a plane strain model was used where the thread is assumed to form through progressive penetration of the blank surface using a parallel set of wedge-shaped indenters. To develop the three-dimensional model, a flat-die rolling process was simulated which incorporated blank rotation, die movement and pitch angle on the die faces. Based on a comparison of thread form and microhardness with as-rolled threads, the plane strain model was found to provide a reasonable approximation of thread-rolling behaviour. Results obtained from the initial pass of the three-dimensional model are promising although progress is currently limited by the excessive computational time needed, frequency of remeshing and sliding at the die-blank interface.

Finite Element Simulation on Stress of Steel Sphere Shell

2012 ◽  
Vol 532-533 ◽  
pp. 297-300
Author(s):  
Chang Li Song ◽  
Jing Ji
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Three Dimensional ◽  
Element Model ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Steel Sphere ◽  
Element Simulation ◽  
Good Agreement

In order to verify correctness of two-dimensional axisymmetric finite element model, this paper carries out axial symmetry analysis of the steel ball shell by ANSYS software and 2-D finite element model is established. The radial and tangential stress distribution is acquired, through comparison with the theoretical solution, both are in good agreement. So it is feasible to simulate the three-dimensional model by finite element axisymmetrical two-dimensional model.

Clinical experience of using virtual 3D modelling for pre and intraoperative guidance during robotic-assisted partial nephrectomy

2021 ◽  
pp. 205141582110002
Author(s):  
Lorenz Berger ◽  
Aziz Gulamhusein ◽  
Eoin Hyde ◽  
Matt Gibb ◽  
Teele Kuusk ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Partial Nephrectomy ◽  
Surgical Outcome ◽  
Prospective Cohort ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Robotic Assisted ◽  
Robotic Assisted Partial Nephrectomy

Objective: Surgical planning for robotic-assisted partial nephrectomy is widely performed using two-dimensional computed tomography images. It is unclear to what extent two-dimensional images fully simulate surgical anatomy and case complexity. To overcome these limitations, software has been developed to reconstruct three-dimensional models from computed tomography data. We present the results of a feasibility study, to explore the role and practicality of virtual three-dimensional modelling (by Innersight Labs) in the context of surgical utility for preoperative and intraoperative use, as well as improving patient involvement. Methods: A prospective study was conducted on patients undergoing robotic-assisted partial nephrectomy at our high volume kidney cancer centre. Approval from a research ethics committee was obtained. Patient demographics and tumour characteristics were collected. Surgical outcome measures were recorded. The value of the three-dimensional model to the surgeon and patient was assessed using a survey. The prospective cohort was compared against a retrospective cohort and cases were individually matched using RENAL (radius, exophytic/endophytic, nearness to collecting system or sinus, anterior/posterior, location relative to polar lines) scores. Results: This study included 22 patients. Three-dimensional modelling was found to be safe for this prospective cohort and resulted in good surgical outcome measures. The mean (standard deviation) console time was 158.6 (35) min and warm ischaemia time was 17.3 (6.3) min. The median (interquartile range) estimated blood loss was 125 (50–237.5) ml. Two procedures were converted to radical nephrectomy due to the risk of positive margins during resection. The median (interquartile range) length of stay was 2 (2–3) days. No postoperative complications were noted and all patients had negative surgical margins. Patients reported improved understanding of their procedure using the three-dimensional model. Conclusion: This study shows the potential benefit of three-dimensional modelling technology with positive uptake from surgeons and patients. Benefits are improved perception of vascular anatomy and resection approach, and procedure understanding by patients. A randomised controlled trial is needed to evaluate the technology further. Level of evidence: 2b

scholarly journals FEM analysis of a new miniplate: stress distribution on the plate, screws and the bone

2012 ◽  
Vol 06 (01) ◽  
pp. 009-015 ◽  
Author(s):  
Didem Nalbantgil ◽  
Murat Tozlu ◽  
Fulya Ozdemir ◽  
Mehmet Oguz Oztoprak ◽  
Tulin Arun
Keyword(s):  
Finite Element ◽  
Cortical Bone ◽  
Three Dimensional ◽  
Fem Analysis ◽  
Force Distribution ◽  
Bone Surface ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

ABSTRACTObjectives: Non-homogeneous force distribution along the miniplates and the screws is an unsolved question for skeletal anchorage in orthodontics. To overcome this issue, a miniplate structure was designed featuring spikes placed on the surface facing the cortical bone. The aim of this study was to examine and compare the force distribution of the newly designed plate-screw systems with the conventional one.Methods: A model of bone surface with 1.5 mm cortical thickness, along with the two newly designed miniplates and a standard miniplate-screw were simulated on the three-dimensional model. 200 g experimental force was applied to the tip of the miniplates and the consequential effects on the screws and cortical bone was evaluated using three-dimensional finite element method.Results: As a result of this finite element study, remarkably lower stresses were observed on the screws and the cortical bone around the screws with the newly designed miniplate when compared with the conventional one.Conclusion: The newly designed miniplate that has spikes was found effective in reducing the stress on and around the screws and the force was distributed more equivalently. (Eur J Dent 2012;6:9-15)

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