scholarly journals Investigation and Improvement of Bursting Force Equations in Posttensioned Anchorage Zone

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Young Hak Lee ◽  
Min Sook Kim
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Parametric Analysis ◽  
Local Stress ◽  
Element Analysis ◽  
Bearing Plate ◽  
Concrete Members ◽  
Transverse Tensile ◽  
Posttensioned Concrete ◽  
Eccentric Distance

In posttensioned concrete members, the high local stress under the anchorage causes transverse tensile stress. Therefore, it is very important to predict the bursting force to determine appropriate reinforcement details. In the present work, the existing equations of the bursting force for the anchorage zone were evaluated and an equation for the bursting force based on finite element analysis was proposed to improve the model’s accuracy. Parametric analysis was performed considering the anchorage shape, tendon angle, and eccentric distance. The analytical results indicate that the existing equations underestimate or overestimate the bursting force. The proposed equation is able to predict the bursting force reasonably well for an anchorage zone with rectangular bearing plate, cavity, and eccentric distance.

Estimation of transverse tensile behavior of Zircaloy pressure tubes using ring-tensile test and finite element analysis

2012 ◽  
Vol 227 (6) ◽  
pp. 1177-1186 ◽  
Author(s):  
MK Samal ◽  
KS Balakrishnan ◽  
J Parashar ◽  
GP Tiwari ◽  
S Anantharaman
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Tensile Tests ◽  
Tensile Specimen ◽  
Displacement Curve ◽  
Stress Strain ◽  
Element Analysis ◽  
Transverse Tensile ◽  
Pressure Tubes ◽  
Load Displacement

Determination of transverse mechanical properties from the ring type of specimens directly machined from the nuclear reactor pressure tubes is not straightforward. It is due to the presence of combined membrane as well as bending stresses arising in the loaded condition because of the curvature of the specimen. These tubes are manufactured through a complicated process of pilgering and heat treatment and hence, the transverse properties need to be determined in the as-manufactured condition. It may not also be possible to machine small miniaturized specimen in the circumferential direction especially in the irradiated condition. In this work, we have performed ring-tensile tests on the un-irradiated ring tensile specimen using two split semi-cylindrical mandrels as the loading device. A three-dimensional finite element analysis was performed in order to determine the material true stress–strain curve by comparing experimental load–displacement data with those predicted by finite element analysis. In order to validate the methodology, miniaturized tensile specimens were machined from these tubes and tested. It was observed that the stress–strain data as obtained from ring tensile specimen could describe the load–displacement curve of the miniaturized flat tensile specimen very well. However, it was noted that the engineering stress–strain as directly obtained from the experimental load–displacement curves of the ring tensile tests were very different from that of the miniaturized specimen. This important aspect has been resolved in this work through the use of an innovative type of 3-piece loading mandrel.

The Establishing and Structural Analysis for Torque Shaft of the Shearer Based on Inventor and Algor

2013 ◽  
Vol 397-400 ◽  
pp. 662-667
Author(s):  
Jian Zhang ◽  
Xiang Xiang Zhang ◽  
Xiao Ying Liu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Parametric Analysis ◽  
Groove Depth ◽  
Dual Function ◽  
Analysis Software ◽  
Element Analysis ◽  
Model Interaction ◽  
Overload Protection ◽  
Torque Transmission

The torque shaft of shearer cutting part plays a dual-function of torque transmission and overload protection when the Shearer is working. Therefore it is necessary to study the reliability of the torque shaft. First, the parameterized torque shaft model was built on Inventor and simple parametric analysis of the torque shaft was done by its finite element analysis module. The unloading groove depth 5.079mm met the overload protection requirements. Then the model was imported into professional finite element analysis software Algor to verify the results. Linear statics analysis in Algor showed that when unloading groove depth valued 5.479mm the torque shaft would be broken once the shearer overload. The results of the analysis were reliable as no data was lost during the model interaction between Inventor and Algor.

Design by Finite Element Analysis on Tubesheet of Heat Exchanger With a Central Hole

2011 ◽  
Author(s):  
Guo Li ◽  
Jianping Zhao
Keyword(s):  
Heat Transfer ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Thermal Stress ◽  
Heat Exchanger ◽  
Local Stress ◽  
Central Hole ◽  
Shell Side ◽  
Element Analysis ◽  
Local Stress Concentration

As one of major components of heat exchanger, tubesheet is of paramount importance to enhance the safety of heat exchanger whether its design is reasonable. As the diversity of the heat exchangers’ operating condition, structures of tubesheets also become very special. A fixed tubesheet heat exchanger with a central pipe whose diameter is greater than other heat exchanger tubes is presented in this paper. A central hole in tubesheet will weaken the stiffness and intensity of the tubesheet and cause local stress concentration along the central hole’s edge. However, there is no design method for this kind of tubesheet with a central hole and it is unable to be calculated using various international standards available. In this paper, finite element analysis code ANSYS is used to simulate the real complex structure, real loads and boundary conditions of the tubesheet so that the design problem can be visualized. The three-dimensional finite element model of the tubesheet is built considering the influence of tube channel, partial shell and heat transfer tube bundle. The different pressure in shell-side and tube-side will cause the mechanical stress. The temperature gradient exists widely and the tubesheet, shell as well as heat transfer tubes can’t transform freely. Therefore, there may exists high thermal stress due to the high temperature difference in shell-side and tube-side. The thermal stress has great impact on the total stress distribution. So the simulation of the temperature field is very important. By means of thermal analysis coupling with structure analysis, the distribution of temperature, stress and deformation is obtained. Through evaluating the stress intensity of the tubesheet, it is found that the dangerous region is located at the edge of the tube distribution region and local stress concentration along the edge of the central hole is not obvious. The result shows that the tubesheet is appropriately designed and the design by finite element analysis method is feasible. This paper provides a solution for this kind of structure’s analysis design in engineering application.

Ductile Fracture Modeling of DH36 Grade Steels

2018 ◽  
Author(s):  
Burak Can Cerik ◽  
Sung-Ju Park ◽  
Joonmo Choung
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Fracture Surface ◽  
Ductile Fracture ◽  
Stress Triaxiality ◽  
Local Stress ◽  
Fracture Initiation ◽  
Isotropic Hardening ◽  
Flow Rule ◽  
Element Analysis

A Hosford-Coulomb type ductile fracture surface was developed for DH36 grade steels. The fracture experiments reported in the literature, which consist of tests with notched tensile specimens, tensile specimens with a central hole, shear specimen and disc specimens for punch specimens, were utilized in a detailed finite element analysis of each experiment to evaluate the evolution of local stress and strain fields and identify plasticity and fracture response of DH36. The developed plasticity model consists of a von Mises yield surface, an associated flow rule and a combined Swift-Voce type isotropic hardening rule. The loading paths to fracture initiation were determined in terms of stress triaxiality and normalized Lode angle parameter histories. Finally, the Hosford-Coulomb fracture surface was calibrated using the finite element analysis results and adapting a linear damage accumulation law.

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