Solid Modeling System Research Articles

Increasing the energy efficiency of wooden house construction

Individual housing construction in the Krasnoyarsk Territory is actively developing. Rising housing prices in multi-storey buildings, increasing building density, and socio-demographic factors are increasing the popularity of individual construction. Technologies for such construction imply the widespread use of available local building materials, in particular wood. During the study, the designs of private houses in the settlement - the regional center of the Krasnoyarsk Territory - were analyzed. It was found that 90% of the sample examined were houses built from timber. Using simulation modeling methods, the actual thermal resistance of the enclosing structure made of timber with a cross-section of 0.15×0.15 m was determined. The calculated value was compared with the standard resistance indicator of the enclosing structure, taking into account energy saving standards. The Elcut solid modeling system was used in the work. The required heat flow power to maintain stationary heat transfer conditions was determined. It has been established that the design enclosing structure does not provide the required thermal resistance taking into account energy saving standards. It is necessary to consider a multilayer enclosing structure and increase the design resistance by insulating the outer surface of the wall with heat-insulating materials.

Frame Fabrication of Electric Formula One Car

Abstract: Design, fabrication, and testing of electric formula one car is presented in this paper. The design guidelines are based on the specifications set by the organizer, universities, design of the car was carried out using SOLID MODELLING system. The car was fabricated in the workshop of mechanical and manufacturing engineering. The car has been tested for its performance

Spectral analysis of gas-dynamic characteristics of pulsing gas flows in the exhaust system of a piston engine

THE PURPOSE. To On the basis of spectral analysis, to evaluate the effect of installing a turbocharger turbine on the aeromechanics of pulsating gas flows in the engine exhaust system and to propose a method for controlling the aerodynamic and heat transfer characteristics of unsteady gas flows by creating an ejection effect in the exhaust system.METHODS. A laboratory experiment on a full-scale piston engine model was chosen to achieve this goal. Spectral analysis of harmonic dependences was used to assess changes in the structure of gas flows in the exhaust system. Mathematical modeling of the operating cycle of diesel engines was used to assess the potential positive effects of the use of an ejection system in the exhaust tract of a diesel engine. Three-dimensional solid modeling systems were used for sketch (engineering) studies of new (modernized) exhaust system designs.RESULTS. The article describes laboratory equipment, measuring system and data processing methods. A description of the boundary conditions in the course of experimental research is given. Comparison of aeromechanical and heat exchange characteristics of unsteady flows in the exhaust system of an engine with and without a turbocharger is carried out in the article. The qualitative and quantitative differences in aeromechanics and thermal physics of processes are shown. The proposed method of aeromechanical improvement of the exhaust system by creating an ejection.CONCLUSION. It was revealed that the turbine of a turbocharger has a significant effect on the aeromechanical characteristics of flows in the exhaust system. A significant decrease in the maximum flow rate in the exhaust tract (up to 3 times) is observed when installing a turbocharger. There is a decrease in flow characteristics through the turbocharged exhaust system (within 30%). It was found that the ejection effect in the engine exhaust system leads to stabilization of the flow, an increase in gas consumption by 6-12%, a decrease in specific fuel consumption by an average of 1% and an improvement in reliability indicators by 1.11-1.74%.

Convex polyhedral meshing for robust solid modeling

We introduce a new technique to create a mesh of convex polyhedra representing the interior volume of a triangulated input surface. Our approach is particularly tolerant to defects in the input, which is allowed to self-intersect, to be non-manifold, disconnected, and to contain surface holes and gaps. We guarantee that the input surface is exactly represented as the union of polygonal facets of the output volume mesh. Thanks to our algorithm, traditionally difficult solid modeling operations such as mesh booleans and Minkowski sums become surprisingly robust and easy to implement, even if the input has defects. Our technique leverages on the recent concept of indirect geometric predicate to provide an unprecedented combination of guaranteed robustness and speed, thus enabling the practical implementation of robust though flexible solid modeling systems. We have extensively tested our method on all the 10000 models of the Thingi10k dataset, and concluded that no existing method provides comparable robustness, precision and performances.

SolidWorks як інноваційний засіб вивчення дисциплін автомобільного профілю

Розроблена методика, яка використовує SolidWorks як засіб навчання з технічних дисциплін автомобільного профілю: твердотільне 3D проектування й моделювання вузлів і деталей автомобільної техніки та пристосувань на перших курсах навчання (SolidWorks); міцнісні, стійкісні, втомні та інші інженерні розрахунки цих вузлів і деталей – на наступних (SolidWorks-додатки).

Solid Modeling and Dynamic Analysis of Mechanisms of Press-forging Machines

Based on the example of AV1818 machine for cold die forging the paper considers the matters of complex use of solid modeling systems (Autodesk Inventor Professional) and the dynamic analysis of mechanisms (DAM) to solve problems associated with the performance forecasting of forge-and-pressing equipment at the stage of their design. The dynamic processes in the mechanisms, primarily, the dynamic forces and positioning accuracy of units are defined based on the models representing systems of point masses connected with elastic ties. Basic parameter computation for the objects of models (units of mechanisms or their fragments): inertia (mass or inertia moment) and elasticity (rigidity at strain-compression, bend or torsion) is a rather complicated task solved with the methods of theoretical mechanics and resistance of materials. The procedure suggested in the work allows increasing the accuracy of calculations and decreasing their complexity at the expense of the final element method (FEM) to solid models of these objects.

Research on Fruit's 3D Solid Modeling and Simulation System

In this study, It takes the selection of tomato fruit appearance acquisition equipment as the key point, combined with the fruit shape extraction algorithm, discussing the establishment of the model of tomato. It is very necessary to design and simulate the life process and production process of tomato by using digital technology and constructing digital tomato technology system. At the same time, it explained the model's process design and function of the simulation system, based on the introduction of the morphological development of tomato. Tomato is one of the most common fruits and vegetables that are cultivated in the world.

Computer Simulation Methods for Crushing Process in an Jaw Crusher

One of the trends at modern mining enterprises is the application of combined systems for extraction and transportation of the rock mass. Given technology involves the use the conveyor lines as a continuous link of combined technology. The application of a conveyor transport provides significant reduction of costs for energy resources, increase in labor productivity and process automation. However, the use of a conveyor transport provides for certain requirements for the quality of transported material. The maximum size of the rock mass pieces is one of the basic parameters for it. The crushing plants applies as a coarse crushing followed by crushing the material to the maximum size of piece which possible to use for conveyor transport. It is often represented by jaw crushers. Modelling of crushing process in jaw crushers allows to maximally optimize workflow and increase efficiency of the equipment at the further transportation and processing of rocks.We studied the interaction between walls of the jaw crusher and bulk material by using discrete element method (DEM) in this paper. The article examines the process of modeling by stages. It includes design of the crusher construction in solid and surface modeling system. Modelling of the crushing process based on the experimental data received via the crushing unit BOYD. The process of destruction and particle size distribution in the study was done. Analysis of research results shows a comparability of actual experiment and modeling process.

The Method of Tolerance Analysis Base on the Monte Carlo

The primary goal of concurrent engineering is to minimize the time spend and to reduce quality problems encountered between a product's conception and customer use, thereby minimizing cost and maximizing product quality. Tolerance is an important index of product design and manufacture. Although they are small as compared with part dimensions, tolerances can propagate and accumulate in an assembly affecting the product assimilability. Moreover, tolerance is inevitable because manufacturing exactly equal parts is known to be impossible. This paper presents a brief review of statistical tolerance and clearance analysis for the assembly, and proposes a method of tolerance analysis by a leading commercial computer-aided tolerance (CAT) analysis system, VisVSA. This method can ensure assembly precision requirements, and design optimally tolerance distribution based on Monte Carlo simulation, take a example of brake assembly to detailed introduce the use of this method. The purpose of this article is expected to make the following contributions: (i) to help the designers to evaluate products for assimilability, (ii) to provide a new perspective to tolerance problems, and (iii) to provide a tolerance analysis tool, VisVSA, which can be incorporated into a CAD or solid modeling system.

Reliable detection and separation of components for solid objects defined with scalar fields

The detection of the number of disjoint components is a well-known procedure for surface objects. However, this problem has not been solved for solid models defined with scalar fields in the so-called implicit form. In this paper, we present a technique which allows for detection of the number of disjoint components with a predefined tolerance for an object defined with a single scalar function. The core of the technique is a reliable continuation of the spatial enumeration based on the interval methods. We also present several methods for separation of components using set-theoretic operations for further handling these components individually in a solid modelling system dealing with objects defined with scalar fields.

Geometric Sketch Constraint Solving with User Feedback

Modern CAD systems rely on two-dimensional sketches as the basis for the creation of most three-dimensional geometry. These sketches consist of qualitative shape information as well as a series of constraints to quantify the exact size and shape of the various segments, arcs, and splines that comprise the sketch. Example constraints include overall lengths, symmetries, parallel and/or perpendicular segments, and arc radii. For a given sketch, there are many sets of constraints that unambiguously define the shape. Unfortunately, sometimes a user prescribes a set of constraints that do not allow the sketch to be solved. Providing feedback to the user as to how to change the constraint definitions to remedy the problem is still a largely unsolved problem. Herein is described a series of techniques for helping a user diagnose sketch problems and provide to the user a series of options that will cause the sketch to be properly solved. The techniques are incorporated in the OpenCSM solid modeling system. Several sample configurations that use these techniques are shown, with a description of the user interaction that the system provides.

Role of the behavioural analysis in the product repair and replacement process: the preliminaries

Current product representation schema in any solid modelling system consists of product’s geometrical (structural) and topological information only. Unless the functional, behavioural and causal information related to the product, is either explicitly described or derived from knowledge of the structure and topology, the overall behaviours of the product (more importantly, its faulty behaviour which must be recognised before any repair or replacement activity could take place) and their causes are difficult to recognise. The paper discusses the preliminaries of functional and behavioural information models that need to be attached with the currently available product structure at providing foundations for building a complete and comprehensive information model for any product. A case study involving the design of a pendulum clock has been presented to clarify several design analysis points that will be useful in various repair and replacement-related problem-solving activities in the future.

2213 大規模点群に基づくインタラクティブな形状モデリングシステム(OS4-1 デジタルモックアップ,OS4 デジタルエンジニアリング)

Mid-range and long-range laser scanners are useful for measuring large-scale engineering facilities. In this paper, we discuss a solid modeling system based on point-clouds captured from engineering facilities. When an engineering facility is measured by a laser scanner, the location of the scanner is restricted in most cases. Components of the engineering facility are only scanned from one side, and they are sometimes partially occluded by other components. To construct solid models using incomplete point-clouds, we propose a new image-based modeling approach combined with point-based modeling techniques. Since point-clouds captured by mid/long-range scanners have reflectance values as well as coordinates, their reflectance images can be used for image-based modeling. We show that our image-based modeling approach is useful for interactively complementing missing information. In addition, we show how to extract shape parameters as precisely as possible by considering industrial standards, assembly constraints, and user-specified constraints.

Virtual cutting and optimization of three-axis milling processes

This paper presents generalized process simulation and optimization strategies to predict and improve the performance of three-axis milling operations. Cutter-part engagement conditions are extracted from a solid modeling system, which can handle free form part surfaces found in dies and molds. The cutting force distribution along the engaged cutting edge-part surface is evaluated based on the laws of mechanics of milling. By integrating the distributed force along the cutting edge, total forces, torque and power are either predicted analytically using closed-form solutions, or numerically if the cutting tool shape is discontinuous. Simulation results are then used in a constraint-based optimization scheme to maximize the material removal rate (MRR) by calculating acceptable feedrate levels. The proposed virtual milling system is demonstrated experimentally in milling a stamping die with free form surfaces.

Subdivision termination criteria in subdivision multivariate solvers using dual hyperplanes representations

The need for robust solutions for sets of nonlinear multivariate constraints or equations needs no motivation. Subdivision-based multivariate constraint solvers typically employ the convex hull and subdivision/domain clipping properties of the Bézier/B-spline representation to detect all regions that may contain a feasible solution. Once such a region has been identified, a numerical improvement method is usually applied, which quickly converges to the root. Termination criteria for this subdivision/domain clipping approach are necessary so that, for example, no two roots reside in the same sub-domain (root isolation). This work presents two such termination criteria. The first theoretical criterion identifies subdomains with at most a single solution. This criterion is based on the analysis of the normal cones of the multiviarates and has been known for some time. Yet, a computationally tractable algorithm to examine this criterion has never been proposed. In this paper, we present a dual representation of the normal cones as parallel hyperplanes over the unit hypersphere, which enables us to construct an algorithm for identifying subdomains with at most a single solution. Further, we also offer a second termination criterion, based on the representation of bounding parallel hyperplane pairs, to identify and reject subdomains that contain no solution. We implemented both algorithms in the multivariate solver of the IRIT solid modelling system and present examples using our implementation.

A unified subdivision approach for multi-dimensional non-manifold modeling

This paper presents a new unified subdivision scheme that is defined over a k -simplicial complex in n -D space with k ≤ 3 . We first present a series of definitions to facilitate topological inquiries during the subdivision process. The scheme is derived from the double ( k + 1 ) -directional box splines over k -simplicial domains. Thus, it guarantees a certain level of smoothness in the limit on a regular mesh. The subdivision rules are modified by spatial averaging to guarantee C 1 smoothness near extraordinary cases. Within a single framework, we combine the subdivision rules that can produce 1-, 2-, and 3-manifolds in arbitrary n -D space. Possible solutions for non-manifold regions between the manifolds with different dimensions are suggested as a form of selective subdivision rules according to user preference. We briefly describe the subdivision matrix analysis to ensure a reasonable smoothness across extraordinary topologies, and empirical results support our assumption. In addition, through modifications, we show that the scheme can easily represent objects with singularities, such as cusps, creases, or corners. We further develop local adaptive refinement rules that can achieve level-of-detail control for hierarchical modeling. Our implementation is based on the topological properties of a simplicial domain. Therefore, it is flexible and extendable. We also develop a solid modeling system founded on our subdivision schemes to show potential benefits of our work in industrial design, geometric processing, and other applications.

Modelling and representation of heterogeneous objects based on STEP for layered manufacturing

An approach of modelling and representation of heterogeneous objects based on STEP is presented in this paper. To model a heterogeneous object, boundary representation is used for geometry representation and a feature-related representation is used to represent the material distribution inside the object. Using this modelling method, functions of the current CAD software can be employed for geometry modelling of heterogeneous objects and the material distribution is modelled in the heterogeneous solid modelling system. STEP standard format is used to exchange geometry data between the CAD software and heterogeneous solid modelling system. For material modelling, reference geometric features and material distribution functions are incorporated together such that all the material information and geometry information of the heterogeneous object can be integrated correctly and entirely without the problem arising from too much data.

Identity propagation method for tracing alterations of a topological entity in a history-based solid modeling system

In a history-based parametric modeling system, the mechanism for naming topological entities is a key component for generating design variants by re-evaluation. During the process of re-evaluation, topological entities may be split, merged, or obliterated. Thus, it is a principal functional request for a naming mechanism to trace such alterations of topological entities. A data structure called a name propagation graph (NPG) is introduced to represent the identity propagation of topological entities. Rules and algorithms are also presented to identify the genetic entities, which originate from the entities on the original version of a part model. Our approach has been implemented in a history-based and feature-based modeling system.

A human–computer system for collaborative design (HCSCD)

This research paper presents a human–computer system for collaborative design (HCSCD). The developed system provides users with a flexible virtual collaborative environment for product design and development. An effective collaborative design requires sharing information and resources between different people and organisations; therefore, it needs not only groupware but also a highly interactive integrated human–computer interface. Hence, these solutions need to expand beyond the currently existing and relatively restrictive tools to a fully integrated and flexible interface based on human aspects. HCSCD encompasses a marketing information system (MIS), a human resource management (HRM) system, a communication system, and an integrated product development solid modelling system. The integrated product development solid modelling system comprised of a computer aided design (CAD) module, an electronic document management (EDM) module, and a database module. The developed HCSCD system was validated using a case study.

Automatic p-version mesh generation for curved domains

To achieve the exponential rates of convergence possible with the p-version finite element method requires properly constructed meshes. In the case of piecewise smooth domains, these meshes are characterized by having large curved elements over smooth portions of the domain and geometrically graded curved elements to isolate the edge and vertex singularities that are of interest. This paper presents a procedure under development for the automatic generation of such meshes for general three-dimensional domains defined in solid modeling systems. Two key steps in the procedure are the determination of the singular model edges and vertices, and the creation of geometrically graded elements around those entities. The other key step is the use of general curved element mesh modification procedures to correct any invalid elements created by the curving of mesh entities on the model boundary, which is required to ensure a properly geometric approximation of the domain. Example meshes are included to demonstrate the features of the procedure.