Use of Sub-Modeling Techniques to Calculate Peak Stresses in Bolt Head-to-Shank Fillet Radius

2008 ◽  
Author(s):  
Richard E. Smith ◽  
Stephen J. Speicher
Keyword(s):  
Three Dimensional ◽  
Structural Response ◽  
Peak Stress ◽  
Finite Element Models ◽  
Stress Concentrations ◽  
Sufficient Detail ◽  
Structural Details ◽  
Modeling Techniques ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

There is an ever-increasing use of three-dimensional finite element models in the field of structural analysis to simulate structural response of complex geometries. Although these models are effective in simulating gross structural behavior, they are oftentimes not able to include sufficient detail to simulate small structural details where stress concentrations can occur. To overcome this limitation, sub-models can be used to calculate stresses in areas of peak stress. This paper discusses the process involved in calculating peak stresses in bolt head-to-shank interfaces using sub-modeling methods.

Three-Dimensional Analysis of Double Rivet-Row Lap Joints: Part II — Countersunk Rivets

2001 ◽  
Author(s):  
K. Iyer ◽  
C. A. Rubin ◽  
G. T. Hahn
Keyword(s):  
Three Dimensional ◽  
Peak Stress ◽  
Companion Paper ◽  
Lap Joints ◽  
Lap Joint ◽  
Stress Concentrations ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Stress Concentration Factors ◽  
Three Dimensional Finite Element

Abstract Three-dimensional finite element analysis of an elastic, double rivet-row, aluminum alloy lap joint with countersunk, aluminum and steel rivets, is presented. Relations between the connection compliance, rivet deformation, peak contact pressures and slip amplitudes, in the absence of interference and clamp-up, are described. Analysis of a connection with non-countersunk rivets is presented in a companion paper. The trends seen in the results are similar to those obtained with non-countersunk rivets, although the peak stress concentrations in the present case are much higher. A superposition approach for estimating stress concentration factors in the panels of multi-row riveted connections with standard or countersunk rivets is presented.

scholarly journals A Comparative Three-Dimensional Finite Element Study of Two Space Regainers in the Mixed Dentition Stage

2020 ◽  
Vol 14 (01) ◽  
pp. 107-114
Author(s):  
Mohamed Ahmed Abdel Hakim ◽  
Nagwa Mohamed Ali Khatab ◽  
Kareem Maher Gaber Mohamed ◽  
Ahmad Abdel Hamid Elheeny
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Three Dimensional ◽  
The Other ◽  
Mixed Dentition ◽  
Von Mises Stress ◽  
Stress Concentrations ◽  
Permanent Molar ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Abstract Objectives This study aims to compare the stress distribution and displacement that resulted from the use of a Gerber space regainer and sagittal distalizer using three-dimensional finite element analysis. Materials and Methods Three-dimensional simulated models of the appliances were developed using a software. The forces applied by the two appliances were 3N (tipping) and 15N (bodily), respectively. Displacement and von Mises stress on the compact and cancellous bone, periodontal ligament (PDL), crowns of the mandibular first, second permanent molars, and deciduous canines were calculated. Stress distribution and displacement values were measured via linear static analysis. Results Gerber space regainer showed greater displacement than that produced by the sagittal distalizer at the first permanent molar. However, such displacement was less at the other tested points when compared with that delivered by sagittal distalizer. The stresses created by Gerber appliance were higher in the crown and PDL of the deciduous canine than the crown of the first permanent molar crown. Conclusions Gerber appliance generates more distal force and less stress concentration on the crown of the mandibular first permanent molar than that created by the sagittal distalizer. On the other hand, stress concentrations produced by Gerber space regainer are found to be more on the crown and PDL of the deciduous canine. Therefore, it can be concluded that the use of Gerber appliance needs more anchorage.

Analytical Study of Fatigue Cracking in Coped Stringers of Steel Bridges

2019 ◽  
Vol 2673 (10) ◽  
pp. 239-246
Author(s):  
Alireza Mohammadi ◽  
Walid S. Najjar
Keyword(s):  
Tensile Stress ◽  
Stress Reduction ◽  
Analytical Study ◽  
Three Dimensional ◽  
Fatigue Cracking ◽  
Hole Drilling ◽  
Finite Element Models ◽  
High Concentration ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Typical coped stringers of streel bridges are prone to fatigue cracking as a result of the high concentration of tensile stress in the cope zone. This stress concentration is caused by a combination of geometric discontinuity at the cope radius and end-connection rigidity. Few retrofit methods are available for mitigating this cracking; they include hole drilling at a crack tip, and top-rivet removal from a stringer-floorbeam connection. Three-dimensional finite element models of a typical stringer with coped web were developed and analyzed to evaluate (i) cope geometry and load configuration parameters and (ii) the effectiveness of these two retrofit methods. The studied geometry parameters were cope radius and cope length. Variations in the cope-zone stress distribution for each parameter and between an original and a retrofitted condition are presented in this paper. Tensile stress reduction was associated with increased cope radius. Although hole drilling resulted in significant stress reduction along the cope edge, this method was associated with increased tensile stress at the bottom of the drilled hole, which could result in further crack propagation. This finding is consistent with existing studies. Removal of a top rivet resulted in significant reduction of tensile stress.

FINITE ELEMENT ANALYSIS OF THE THERMAL BEHAVIOUR OF SINGLE-DISC CLUTCHES DURING REPEATED ENGAGEMENTS

Tribologia ◽  
2016 ◽  
Vol 266 (2) ◽  
pp. 9-24 ◽  
Author(s):  
Oday I. ABDULLAH ◽  
Laith Abed SABRI ◽  
Wassan S. Abd Al-SAHB
Keyword(s):  
Finite Element ◽  
Thermal Behaviour ◽  
Thermal Stresses ◽  
Three Dimensional ◽  
Finite Element Models ◽  
Element Analysis ◽  
Premature Failure ◽  
Friction Clutch ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Most of the failures in the sliding systems occur due to the high thermal stresses, which generated at the interface between the contacting surfaces due to sliding between parts, such as friction clutches and brakes. In this paper, the thermal behaviour of a single-disc clutch is investigated. The surface temperatures of the friction clutch disc will be increased during repeated engagements, in some cases, will lead to premature failure of the clutch disc. In order to avoid this kind of failure, it the surface temperature should be calculated with high accuracy to know the maximum working temperature of the friction system. In this work, the temperature distributions are computed during four repeated engagements at regular intervals (5 s) for the same energy dissipation. Three-dimensional finite element models are used to simulate the typical friction clutch disc.

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