scholarly journals Dynamic Motion Simulation: Applications in Forensic Engineering

2020 ◽  
Vol 36 (1) ◽  
Author(s):  
Mark Webster
Keyword(s):  
Computer Aided Design ◽  
Laser Scanning ◽  
Accurate Determination ◽  
Motion Simulation ◽  
Dynamic Motion ◽  
Mass Properties ◽  
Forensic Engineering ◽  
Scan Data ◽  
Aided Design

A worker was injured when a large sculpture overturned while it was being transferred on a wheeled cart from a delivery truck onto a dock lift. This paper introduces the use of dynamic motion simulation (DMS) soft-ware as a forensic engineering tool for analyzing and simulating motion/contact between multiple interacting physical objects. Important inputs to the software include the mass properties of the objects — in this case, a very irregularly shaped sculpture. For simple shapes, the distribution of mass can easily be approximated by manually discretizing the object into several smaller, simpler shapes. Accurate determination of the mass dis-tribution of an irregular shape (such as a sculpture) can be aided by measurement methods such as the laser scanning process used in this case. The resulting scan data was used to create a 3-D computer model that was processed using conventional mechanical computer-aided design (CAD) and DMS software to determine the mass properties and ultimately to simulate the dynamic motion.

Designing of Outriggers for the Needs of the Vehicles Stability Testing

2018 ◽  
Vol 875 ◽  
pp. 71-76
Author(s):  
Victor Kryaskov ◽  
Andrey Vashurin ◽  
Anton Tumasov ◽  
Alexey Vasiliev
Keyword(s):  
Coefficient Of Friction ◽  
Computer Aided Design ◽  
Strength Analysis ◽  
Direct Impact ◽  
Stability Testing ◽  
Supporting Surface ◽  
Stability Tests ◽  
Computer Aided ◽  
Aided Design

This paper is dedicated to the issues of designing of outriggers for avoidance of vehicle tilting during its stability tests. An analysis of existing types of outriggers was done by authors as well as legislative requirements on them. The reliable and well-timed operation of outriggers largely depends on the height of their positioning on a vehicle. In order to determine this important parameter a special methodic of determining the tipping angle of the vehicle with the use of computer-aided design (CAD) was composed by authors. The article also contains some main principles of strength analysis of the structure a very important part of which became the necessity of determination of coefficient of friction between the outrigger sliders and the supporting surface. This coefficient has a direct impact on the value of transverse forces appearing at the ends of outrigger beams.

scholarly journals Digital Workflow to Fabricate Complete Dentures for Edentulous Patients Using a Reversing and Superimposing Technique

2021 ◽  
Vol 11 (13) ◽  
pp. 5786
Author(s):  
Hwa-Jung Lee ◽  
Jeongho Jeon ◽  
Hong Seok Moon ◽  
Kyung Chul Oh
Keyword(s):  
Additive Manufacturing ◽  
Computer Aided Design ◽  
Digital Data ◽  
Complete Dentures ◽  
Intraoral Scanner ◽  
Digital Workflow ◽  
Denture Base ◽  
Scan Data ◽  
Edentulous Patients ◽  
Aided Design

This technical procedure demonstrates a 4-step completely digital workflow for the fabrication of complete dentures in edentulous patients. The digital scan data of the edentulous arches were obtained using an intraoral scanner, followed by the fabrication of modeless trial denture bases using additive manufacturing. Using the trial denture base and a wax rim assembly, the interarch relationship was recorded. This record was digitized using an intraoral scanner and reversed for each maxillary and mandibular section individually. The digital scan data directly obtained using the intraoral scanner were superimposed over the reversed data, establishing a proper interarch relationship. The artificial teeth were arranged virtually and try-in dentures were additively manufactured. Subsequently, the gingival and tooth sections were additively manufactured individually and characterized. Thus, fabrication of digital complete dentures can be accomplished using digital data characteristics. The workflow includes data acquisition using an intraoral scanner, data processing using reverse engineering and computer-aided design software programs, and additive manufacturing.

Determination of the Workspace of a Three-Degrees-of-Freedom Parallel Manipulator Using a Three-Dimensional Computer-Aided-Design Software Package and the Concept of Virtual Chains1

2015 ◽  
Vol 8 (2) ◽  
Author(s):  
Andrew Johnson ◽  
Xianwen Kong ◽  
James Ritchie
Keyword(s):  
Computer Aided Design ◽  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Graphical Representation ◽  
Three Dimensional ◽  
Parallel Manipulators ◽  
Workspace Analysis ◽  
Computer Aided ◽  
Aided Design

The determination of workspace is an essential step in the development of parallel manipulators. By extending the virtual-chain (VC) approach to the type synthesis of parallel manipulators, this technical brief proposes a VC approach to the workspace analysis of parallel manipulators. This method is first outlined before being illustrated by the production of a three-dimensional (3D) computer-aided-design (CAD) model of a 3-RPS parallel manipulator and evaluating it for the workspace of the manipulator. Here, R, P and S denote revolute, prismatic and spherical joints respectively. The VC represents the motion capability of moving platform of a manipulator and is shown to be very useful in the production of a graphical representation of the workspace. Using this approach, the link interferences and certain transmission indices can be easily taken into consideration in determining the workspace of a parallel manipulator.

scholarly journals COMPLEX USAGE OF 4D INFORMATION MODELLING CONCEPT FOR BUILDING DESIGN, ESTIMATION, SHEDULING AND DETERMINATION OF EFFECTIVE VARIANT

2006 ◽  
Vol 12 (2) ◽  
pp. 91-98 ◽  
Author(s):  
Vladimir Popov ◽  
Saulius Mikalauskas ◽  
Darius Migilinskas ◽  
Povilas Vainiūnas
Keyword(s):  
Computer Aided Design ◽  
Information Technologies ◽  
Investment Project ◽  
Building Design ◽  
Product Lifecycle Management ◽  
Information Modeling ◽  
Information Modelling ◽  
Computer Aided ◽  
Aided Design

With the growth of information technologies in the field of construction industry, the concept of CAD (Computer Aided Design), which denotes just design operations using a computer acquires a new meaning and changes the contents lightening design process based on product modelling and further numerical simulation construction process and facility managing. New definitions as Building Information Modelling (BIM) and Product Lifecycle Management (PLM) are more and more usable as the definition of a new way approaching the design and documentation managing of building projects. The presented computer aided design technology based on the concept of graphical ‐ information modeling of a building, is combined with resource demand calculations, comparison of alternatives and determination of duration of all the stages of investment project life. The software based on this combined 4D PLM model is to be created as a means to manage effectively the investment project, starting from planning, designing, economical calculations, construction and afterwards to manage the finished building and to utilize it.

Classification Systems for Ship Items: A Formal Approach and Its Application

1988 ◽  
Vol 25 (01) ◽  
pp. 67-73
Author(s):  
Adrian Birbanescu-Biran
Keyword(s):  
Computer Aided Design ◽  
Classification Systems ◽  
Level Of Detail ◽  
Design System ◽  
Formal Approach ◽  
Damage Stability ◽  
Mass Properties ◽  
Formal Definitions ◽  
Aided Design ◽  
Hierarchic System

Calculation of masses and moments of ship items is carried out mainly to establish the main ship dimensions, to assess intact and damage stability and to estimate cost. The mass properties of ship items can be systematically summed over subgroups, groups, and main groups of items if these are classified according to a hierarchical system. The process can be facilitated and eventually automated by assigning each item a classification number that induces the desired hierarchic system. Formal definitions and conventions are presented for constructing such numbers. Accepted classification systems such as SWBS, MARAD, and SFI were analyzed briefly in the light of the proposed formalism and corrections were proposed for the MARAD system. The results of this analysis were used to develop a program for summing mass properties at the level of detail specified by the user, that is, at the level of subgroups, groups, or main groups of ship items. This program was written as part of a computer-aided design system integrated around a relational database. The availability of the program also enabled a significant reduction of the redundancy of stored data.

Determination of the Milling Conditions of a Pump Casing Cover Using a Parametric Designed Fixture Device

2015 ◽  
Vol 809-810 ◽  
pp. 890-895
Author(s):  
Ionuţ Ghionea ◽  
Adrian Ghionea ◽  
Saša Ćuković ◽  
Nicolae Ionescu
Keyword(s):  
Working Conditions ◽  
Computer Aided Design ◽  
Fem Analysis ◽  
Milling Process ◽  
Milling Tool ◽  
Cutting Force Components ◽  
Force Components ◽  
Aided Design ◽  
Tool Diameter

This paper presents an applicative methodology of parametric computer aided design using the CATIA v5 software to model and assembly a modular fixture device. The device is then used in the orientation and clamping a part of type casing cover which has a face machined by milling. Having a constructive solution of the fixture device, the next step is to simulate a milling process through a FEM analysis to identify the working conditions: milling tool diameter, number of teeth, cutting forces, required power of the machine tool etc. Some parameters were chosen according to various tools manufacturers catalogues and the cutting force components were determined experimentally in laboratory conditions. The analysis results show that in the FEM simulated milling process, in all the fixture device parts, some tensions cause displacements that have an influence over the casing cover surface roughness.

A Method of Determining the Direction of Two Dimensional Curves

2014 ◽  
Vol 980 ◽  
pp. 159-164
Author(s):  
F. Wang ◽  
R.K.F. Abdelmaguid ◽  
H.M.A. Hussein
Keyword(s):  
Computer Aided Design ◽  
Tangent Vector ◽  
Two Dimensional ◽  
Linear Algorithm ◽  
Complete Cycle ◽  
Angular Change ◽  
Computer Aided ◽  
Aided Design ◽  
Relationship Of

Two-dimensional curves are represented by a list of vertices and other parameters that control the shape or curvature of the segments. In computer programming to deal with closed two-dimensional curves, it is often required to know the direction of the curve, which is reflected by the sequence of the vertex data. It can be anticlockwise or clockwise. This paper presents a robust, linear algorithm to determine the direction of a closed two-dimensional curve, by computing the total angular change of a tangent vector travelling along the curve for a complete cycle. A new, robust linear algorithm is proposed for the determination of the positional relationship of a point to a two-dimensional curve. For curves that consist of line and arc segments, which are most commonly used in engineering applications in computer aided design, the paper presents algorithms and procedures for solving the above problems.

scholarly journals Developing Customized Dental Miniscrew Surgical Template from Thermoplastic Polymer Material Using Image Superimposition, CAD System, and 3D Printing

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Yu-Tzu Wang ◽  
Jian-Hong Yu ◽  
Lun-Jou Lo ◽  
Pin-Hsin Hsu ◽  
CHun-Li Lin
Keyword(s):  
3D Printing ◽  
Polymer Material ◽  
Computer Aided Design ◽  
Laser Scanning ◽  
Clinical Test ◽  
Cad System ◽  
Holding Power ◽  
Surgical Template ◽  
Solid Models ◽  
Aided Design

This study integrates cone-beam computed tomography (CBCT)/laser scan image superposition, computer-aided design (CAD), and 3D printing (3DP) to develop a technology for producing customized dental (orthodontic) miniscrew surgical templates using polymer material. Maxillary bone solid models with the bone and teeth reconstructed using CBCT images and teeth and mucosa outer profile acquired using laser scanning were superimposed to allow miniscrew visual insertion planning and permit surgical template fabrication. The customized surgical template CAD model was fabricated offset based on the teeth/mucosa/bracket contour profiles in the superimposition model and exported to duplicate the plastic template using the 3DP technique and polymer material. An anterior retraction and intrusion clinical test for the maxillary canines/incisors showed that two miniscrews were placed safely and did not produce inflammation or other discomfort symptoms one week after surgery. The fitness between the mucosa and template indicated that the average gap sizes were found smaller than 0.5 mm and confirmed that the surgical template presented good holding power and well-fitting adaption. This study addressed integrating CBCT and laser scan image superposition; CAD and 3DP techniques can be applied to fabricate an accurate customized surgical template for dental orthodontic miniscrews.

Research on 3D Reconstruction of the Facial Surface Reverse Engineering

2011 ◽  
Vol 201-203 ◽  
pp. 113-116 ◽  
Author(s):  
Jie Yang ◽  
Lei Zhao
Keyword(s):  
Computer Aided Design ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Scanning System ◽  
3D Face Reconstruction ◽  
Surface Integration ◽  
Computer Aided ◽  
Point Data ◽  
Aided Design ◽  
Laser Scanning System

According to the surface integration of laser technology and computer-aided design and computer-aided manufacturing technology (CAD & CAM), a method that is rebuilt surface of three-dimensional facial reconstruction has been explored. A laser scanning system is used to collect the 3D discrete point data of the facial model, which will be cut up by their characteristics and curvature in order to make a 3D face reconstruction. The maximum reconstructive error is 0.2174mm. Application results indicate that the proposed method is quite satisfactory for facial reconstructive surgery, rehabilitation design and plastic surgery.

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