scholarly journals Biomechanics in Removable Partial Dentures: A Literature Review of FEA-Based Studies

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Mohammed A. Mousa ◽  
Johari Yap Abdullah ◽  
Nafij B. Jamayet ◽  
Mohamed I. El-Anwar ◽  
Kiran Kumar Ganji ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Literature Review ◽  
Literature Survey ◽  
Dynamic Loads ◽  
Element Analysis ◽  
Biomechanical Stress ◽  
Flexible Materials ◽  
Horizontal Curvature ◽  
Supporting Structures

The present study was aimed at reviewing the studies that used finite element analysis (FEA) to estimate the biomechanical stress arising in removable partial dentures (RPDs) and how to optimize it. A literature survey was conducted for the English full-text articles, which used only FEA to estimate the stress developed in RPDs from Jan 2000 to May 2021. In RPDs, the retaining and supporting structures are subjected to dynamic loads during insertion and removal of the prosthesis as well as during function. The majority of stresses in free-end saddle (FES) RPDs are concentrated in the shoulder of the clasp, the horizontal curvature of the gingival approaching clasp, and the part of the major connector next to terminal abutments. Clasps fabricated from flexible materials were beneficial to eliminate the stress in the abutment, while rigid materials were preferred for major connectors to eliminate the displacement of the prosthesis. In implant-assisted RPD, the implant receive the majority of the load, thereby reducing the stress on the abutment and reducing the displacement of the prosthesis. The amount of stress in the implant decreases with zero or minimal angulation, using long and wide implants, and when the implants are placed in the first molar area.

Weight and configuration optimization of the launcher pod using finite element analysis

2021 ◽  
pp. 154851292110675
Author(s):  
Mithilesh Kumar Dewangan ◽  
S K Panigrahi
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Dynamic Loads ◽  
Initial Weight ◽  
Configuration Optimization ◽  
Element Analysis ◽  
Critical Location ◽  
Strength And Stiffness ◽  
The Given ◽  
Modification Of Materials

This paper deals with the stress analysis of the launcher pod based on optimization of its configuration and weight without compromising its strength and stiffness. The launcher pod assembly is a complex fabricated structure, which is subjected to a variety of dynamic loads during firing of rockets. A series of finite element simulations reveal the critical location of the pod for different loading conditions based on the stress magnitude, which helps to optimize its weight and configuration of the launcher pod. It has been observed that the optimized weight of the given launcher pod after modification of materials and configuration, with the provided materials, loading, and boundary conditions, is reduced by 36.27% (without launcher tubes and rockets) against the initial weight of the launcher pod.

A Review of Optimising the Design of a New Coke Drum Skirt

2019 ◽  
Author(s):  
Alex Berry ◽  
Warren Brown ◽  
Antonio Seijas ◽  
Sarah Cook
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Fatigue Life ◽  
Literature Review ◽  
Thermal Stresses ◽  
Fatigue Cracking ◽  
Element Analysis ◽  
Long Life ◽  
Welded Connection

Abstract Coke drums are subjected to severe thermal cycling with the skirt to shell connection weld being vulnerable to fatigue cracking. It is essential this connection is well designed to ensure a long life before repairs are inevitably required. Much has been written on coke drum skirt design with the aim of reducing the thermal stresses and strains encountered at the skirt connection weld, some designs have removed the weld completely allowing the drum to sit in an “egg-in-cup” arrangement. This paper includes a short literature review discussing Coke drum skirt designs and explains skirt behaviour during the drum cycle that results in eventual skirt cracking. A case study is reviewed in detail for a new pair of coke drums, where the predicted fatigue life of the chosen welded connection is assessed using axisymmetric, quarter symmetry and half symmetry finite element analysis supported by thermocouple data. The optimised design focuses on a conventional tangential design where the effects of the essential variables such as skirt thickness, skirt connection location, skirt-to head-gap and slot design (length, location & spacing) have been modelled and optimised to obtain a skirt design that produces the longest fatigue life for the intended duty cycle. Coke drum skirts must be installed onto the shell to exacting tolerances during manufacture to ensure concentricity and minimal gap between the skirt and shell. A brief overview of how this is achieved will be presented.

Comparative Safety Analysis of Different Bollard Supporting Structures

2013 ◽  
Vol 325-326 ◽  
pp. 1297-1300
Author(s):  
Long Zhang ◽  
Jian Xing Yu ◽  
Wei Lin Ma ◽  
Bao Jian Wang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Safety Analysis ◽  
Ansys Software ◽  
Element Analysis ◽  
Strength Criteria ◽  
Design Load ◽  
Comparative Safety ◽  
Supporting Structures

Detailed finite element analysis has been carried out for different bollard supporting structures by ANSYS software. From the analysis results, it can be seen that the bollard supporting structures are of adequate strength to take the design load transferred from the mooring rope during operation considering the requirement on strength criteria from IACS, and strength check is performed in accordance with the updated relevant ABS standard. Finally, a comparison of these different bollard supporting structures is made to find out their own advantages from safety and other aspects.

Applications of Multi-Point Mirror Supporting

2013 ◽  
Vol 475-476 ◽  
pp. 1555-1558
Author(s):  
Ren Shan Zhuo ◽  
Dong Ge Zhang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Theoretical Studies ◽  
Design Requirement ◽  
Element Analysis ◽  
Primary Mirror ◽  
Supporting System ◽  
System A ◽  
Series Of Experiments ◽  
Supporting Structures

Primary mirror (PM) supporting system design is one of the key components to the design of a telescope. This paper presents applications of extended multi-point supporting structures that are employed in ground based theodolites, 3 points positioning-9 points supporting system and 18 points supporting system. A number of theoretical studies have been performed using Finite Element Analysis (FEA) on each supporting system, in which the extended multi-point supporting system to 0.6-m and 1-m diameter primary mirror is particularly focused. Analyzing Zerodur major mirrors with a diameter to thickness ratio less than 7.3, deformation due to supporting gives an RMS value less than 6-nm which is 24% of the design requirement of 60-nm. Series of experiments have also been conducted using 4-D interferometer. The deformation due to supporting of major mirror has been predominantly suppressed mainly by deformation during the fabrication process. This indicates that the above supporting systems perform an excellent task under given conditions.

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