Geometrical characterization of canted coil springs

Author(s):  
J M Soler ◽  
R H Rangel

This article presents a geometrical description of canted coil springs as a particular type of space curve. The influence of the canted angle on the geometrical curvature and torsion is investigated in order to characterize the three-dimensional geometry of the springs. Geometrical descriptions of helical spring rings generated by joining together the two ends of a rectilinear-axis spring as well as several types of spring rings, obtained from rectilinear-axis canted coil springs, are proposed. To create such ring geometries, conservation of length of wire is assumed and approximate relations are derived in order to simplify computations. These geometrical descriptions are then applied to generate appropriate three-dimensional models. Such models can be further imported to computer-aided design and finite-element analysis programmes in order to estimate the mechanical response of such springs.

Author(s):  
Vladimir Panchenko ◽  
Valeriy Kharchenko

This chapter discusses the simulation of solar photovoltaic thermal modules of planar and concentrator structures in computer-aided design systems KOMPAS 3D and finite element analysis ANSYS. To create photovoltaic thermal modules, a method for designing their three-dimensional models in the computer-aided design system has been developed. To study the thermal regimes of the created three-dimensional models of modules, a method has been developed for visualizing thermal processes, coolant velocity, and flow lines of a cooling agent in a finite element analysis system. As a result of calculations in the finite element analysis system using the developed method, conclusions can be drawn about the feasibility of the design created with its further editing, visualization of thermal fields, and current lines of the radiator cooling agent. As an illustration of the simulation results, a three-dimensional model of a photovoltaic thermal planar roofing panel and an optimized three-dimensional model of a photodetector of a solar concentrator photovoltaic thermal module are presented.


2002 ◽  
Author(s):  
◽  
Jason David De Beer

Today's powerful computer-aided engineering (CAE) products have reached ground breaking levels of sophistication when compared with the almost archaic technology used by our predecessors. Engineers are able to develop complex three-dimensional models, or virtual prototypes, using powerful 3D modelling capabilities, and from these models, generate manufacturing drawings, motion analysis models, and even finite element models.


Author(s):  
Hossam S. Badawi ◽  
Sherif A. Mourad ◽  
Sayed M. Metwalli

Abstract For a Computer Aided Design of a concrete truck mixer, a six cubic meter concrete mixer drum is analyzed using the finite element method. The complex mixer drum structure is subjected to pressure loading resulting from the plain concrete inside the drum, in addition to its own weight. The effect of deceleration of the vehicle and the rotational motion of the drum on the reactions and stresses are also considered. Equivalent static loads are used to represent the dynamic loading effects. Three-dimensional shell elements are used to model the drum, and frame elements are used to represent a ring stiffener around the shell. Membrane forces and bending stresses are obtained for different loading conditions. Results are also compared with approximate analysis. The CAD procedure directly used the available drafting and the results were used effectively in the design of the concrete mixer drum.


2019 ◽  
Vol 53 (3) ◽  
pp. 197-205
Author(s):  
Kshitij Hemant Sabley ◽  
Usha Shenoy ◽  
Sujoy Banerjee ◽  
Pankaj Akhare ◽  
Ananya Hazarey ◽  
...  

Objective: To assess and compare the tensions and deformations (stresses and strains) generated after application of two types of forces (traction and torsion) in miniscrews of two different materials (titanium and stainless steel) placed at five different angulations. Materials and Methods: Three-dimensional models of the posterior maxillary area and the mini-implants were constructed using computer-aided design software program (CATIA P3 V5-6 R2015 B26 / 2016; Dassault Systèmes). Titanium and stainless steel materials were used for miniscrews. The area constructed was in between the maxillary second premolar and first molar. The models with mini-implants were inserted at five different angulations (30°, 45°, 60°, 75° and 90°). Torsional and tractional forces were applied on these implants, and the models were solved using ANSYS 10.0. Stress generated in implant and in the cortical and cancellous bones was evaluated and compared at all the five angulations. Results: Stress generated in stainless steel mini-implant during torsional and linear force application was less when compared with titanium mini-implant. Also, stress generated in implants of both materials increased as the angle increased from 30° to 90°. Difference in stress generated by stainless steel implant in the cortical bone for both linear and torsional forces was less when compared with titanium implant, whereas for cancellous bone, the difference was insignificant at all the angles. Conclusion: Irrespective of angles, difference in stress generated in stainless steel implants and titanium implants for both the forces was not significant, and hence, stainless steel implants can be used effectively in a clinical setting.


Symmetry ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 306 ◽  
Author(s):  
Francisco Cavas-Martínez ◽  
Daniel Fernández-Pacheco ◽  
Francisco Cañavate ◽  
Jose Velázquez-Blázquez ◽  
Jose Bolarín ◽  
...  

The validation of new methods for the diagnosis of incipient cases of Keratoconus (KC) with mild visual limitation is of great interest in the field of ophthalmology. During the asymmetric progression of the disease, the current diagnostic indexes do not record the geometric decompensation of the corneal curvature nor the variation of the spatial profile that occurs in singular points of the cornea. The purpose of this work is to determine the structural characterization of the asymmetry of the disease by using morpho-geometric parameters in KC eyes with mild visual limitation including using an analysis of a patient-specific virtual model with the aid of computer-aided design (CAD) tools. This comparative study included 80 eyes of patients classified as mild KC according to the degree of visual limitation and a control group of 122 eyes of normal patients. The metric with the highest area under the receiver operating characteristic (ROC) curve was the posterior apex deviation. The most prominent correlation was found between the anterior and posterior deviations of the thinnest point for the mild keratoconic cases. This new custom computational approach provides the clinician with a three-dimensional view of the corneal architecture when the visual loss starts to impair.


2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Ennio Bramanti ◽  
Gabriele Cervino ◽  
Floriana Lauritano ◽  
Luca Fiorillo ◽  
Cesare D’Amico ◽  
...  

The aim of this paper is to underline the mechanical properties of dental single crown prosthodontics materials in order to differentiate the possibility of using each material for typical clinical condition and masticatory load. Objective of the investigation is to highlight the stress distribution over different common dental crowns by using computer-aided design software and a three-dimensional virtual model. By using engineering systems of analyses like FEM and Von Mises investigations it has been highlighted the strength over simulated lower first premolar crowns made by chrome cobalt alloy, golden alloy, dental resin, and zirconia. The prosthodontics crown models have been created and put on simulated chewing stresses. The three-dimensional models were subjected to axial and oblique forces and both guaranteed expected results over simulated masticatory cycle. Dental resin presented the low value of fracture while high values have been recorded for the metal alloy and zirconia. Clinicians should choose the better prosthetic solution for the teeth they want to restore and replace. Both prosthetic dental crowns offer long-term success if applied following the manufacture guide limitations and suggestions.


2010 ◽  
Vol 455 ◽  
pp. 283-287
Author(s):  
Chuan Shao Liu ◽  
Jian Xin Zheng ◽  
Y.F. Liu

Acoustic system is the core component of power ultrasonic, which is designed by traditional analytic method and modal analysis with finite element analysis method. And component of the step-like horn with rectangular sections and tool head used in two dimension ultrasonic polishing without abrasives are studied, and the calculating results and modal analysis results are consistent on the whole. The harmonic response analysis for the component of horn and tool head is carried out and the three dimensional coordinates of the vibrating node on the tool head with maximal displacement are obtained. The fitting result shows that the moving trajectory of such node is ellipses, which meets the experimental requirement well. So a new way for designing acoustic system of two dimensional ultrasonic vibration through combining theoretical calculation with computer aided design may be applied.


2020 ◽  
Vol 66 (11) ◽  
pp. 1498-1502
Author(s):  
Thyeres Teixeira Bueno Chrispin ◽  
Marina Silva Fernandez ◽  
Claudia Cristina Takano Novoa ◽  
Marair Gracio Ferreira Sartori

SUMMARY Additive Manufacturing (AM), also known as Rapid Prototyping, is a set of production technologies used in the synthesis of a particular physical object by adding layers to form a part based on data generated by Computer-Aided Design (CAD) systems. These technologies are widely used to quickly create prototypes of products and tools for commercial purposes. Over time, it has also been integrated with other areas, such as healthcare, since these tools have allowed health professionals to assist in diagnoses, surgical planning, and synthesis of orthoses and prostheses for patient rehabilitation. OBJECTIVE: To develop models for the construction of dilators for the treatment of vaginal agenesis. METHODS: Use CAD software and create a physical model using AM to analyze the viability of its production in the elaboration of customized dilators for each patient. RESULTS: The production through AM provides an advantage in the development, facilitating physical alterations just by adjusting the three-dimensional models made by the software in a quick way, thus making the customization process viable. CONCLUSION: The proposed procedure for the manufacture of dilators presented good results and technological feasibility, indicating that it can be a good solution for the production and customization of gynecological devices.


2006 ◽  
Vol 53 (1) ◽  
pp. 42-53 ◽  
Author(s):  
Aleksandar Todorovic ◽  
Vojkan Lazic

CAD/CAM technology (Computer Aided Design / Computer Aided Manufacturing) in the matter of fact helps in design and development of two-dimensional or three-dimensional models and their realization on numerical controlled machines. The key to direct or indirect CAD/CAM dental restorations is the measurement of dental preparation in the mouth or on the plaster die. The aim of this paper is to describe the possibilities and the way of function of different computer aided inspection (CAI) systems as a first part of CAD/CAM systems. Different researchers have presented several approaches of methods for three dimensional (3D) measurement. Today, for chairside dental treatment, only the optical method of measurement has lead to satisfactory results in practice. Laboratory CAD/CAM systems use mechanical and optical technologies for 3D measurement. Optical impression grows as a leader of CAI segment of almost every new CAD/CAM system. The most important properties of 3D scanners are: accuracy, volume and speed of measurement and ergonomy of instrument. .


1990 ◽  
Vol 68 (4) ◽  
pp. 1707-1716 ◽  
Author(s):  
F. G. Spinale ◽  
B. A. Carabello ◽  
F. A. Crawford

Right ventricular (RV) volumetric and morphological analysis is complicated by the trabeculations and geometric configuration of the RV chamber. To improve RV analysis, custom computer-aided design programs were employed to obtain RV volumes and three-dimensional models from biplane ventriculograms. Biplane RV ventriculograms were analyzed from 14 anesthetized dogs and 22 RV casts. Computed volumes were highly correlated with reference RV volumes (r = 0.98, n = 36, P less than 0.01) with a range of 5-73 ml. Three-dimensional wire-frame and solid models constructed from the ventriculographic images provided excellent detail and a new perspective in chamber shape. This modeling technique was then used to examine RV volumes, geometric conformation, and regional shortening in 10 pigs during inotropic stimulation and preload reduction. Changes in RV volumes, ejection fraction, and regional motion were detected as well as alterations in chamber conformation. In summary 1) computer-aided design offers an accurate and simplified means to compute RV volumes using basic microcomputer equipment, and 2) three-dimensional reconstruction provided a unique view of RV geometry and a means to examine regional RV function.


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