Performance comparison of adapted delaunay triangulation method over nurbs for surface optimization problems

Traditionally NURBS (Non-Uniform Rational Basis Spline) are used as the basis for defining free-form surfaces as they can define non-regular surfaces with minimal control points. However, they require parameters such as knot vectors and weights to configure a surface. Similarly, DT (Delaunay Triangulation) is proven and used widely for meshing, rendering and surface reconstruction applications, but its capability in freeform surface design for optimization is untested. Thus, this paper proposes Adapted Delaunay Triangulation (ADT) method which can generate a surface from scattered data points without any parameters. The paper presents a comparison of the performance of ADT method and NURBS fitting method for surface generation from scattered 3D coordinate points. This method was suggested so that the generated surface could be used in Stochastic Optimization Algorithm (SOA) methods and computational fluid dynamics applications (CFD) simultaneously. Data points that other 3D point clouds fitting methods would ignore as outliers are included in ADT method. Small change in each data point during optimization cycle should show a distinctive change in its output as SOA approaches depend on such differences for its optimal performance. Special consideration has been made for fast processing and rendering of the surface with minimum complexity (removing parameters such as knots and weights) and storage requirements as SOA methods demand generation of numerous surfaces to solve any problem

Adapted Delaunay triangulation method for free-form surface generation from random point clouds for stochastic optimization applications

Free-form surfaces are defined with NURBS (non-uniform rational basis spline) for most computer-aided engineering (CAE) applications. The NURBS method requires the definition of parameters such as weights, knot vectors and degree of the curves which make the configuration of the surface computationally expensive and complex. When the control points are randomly spaced in the point cloud and the topology of the desired surface is unknown, surface configuration with NURBS method becomes a challenging task. Optimization attempts for such surfaces create enormous amounts of computing data when coupled with physics solvers such as finite element analysis (FEA) tools and computational fluid dynamics (CFD) tools. In this paper, an adapted Delaunay triangulation (ADT) method for surface generation from the random points cloud is proposed and compared with widely used implicit functions based NURBS fitting method. The surface generated from ADT method can be simultaneously used with stochastic optimization algorithms (SOA) and CFD applications to search for the optimal results with minimum computational costs. It was observed while comparing ADT with NURBS-based geometry configuration that the computation time can be reduced by 3 folds. The corresponding deviation between both geometry configuration methods has been observed as low as 5% for all optimisation scenarios during the comparison. In addition, ADT method can provide light weight CFD approach as any instance of design iteration has at least half storage footprint as compared to corresponding NURBS surface. The proposed approach provides novel methodology towards establishing light weight CFD geometry, absence of which currently isolates methodologies for optimization and CFD analysis

E-learning tools: engaging our students?

Since Generation Z students have grown up around WIFI-laptops, video game, etc. they expect technology to be involved in teaching approaches, however students' perception towards e-learning tools indicate that 80% of students (∼180 students) prefer a face-to-face approach.(undefined

Design and ergonomic analysis of the Waste Electrical and Electronic Equipment (WEEE) remanufacturing workcell fixture using digital mock-up environment

Traditionally, operations in recycling industry such as WEEE (Waste Electrical and Electronic Equipment) are labour intensive and time consuming due to the nature of discrete / non-standards product states. Hence, small-mid scale WEEE recycling companies require significant product state assessment, process design and technology commitment in order to bid for mass refurbishment projects. Employing digital process simulation tools (which is prevalent in automotive and aircraft manufacturing industries) will result in design of ergonomically viable workstations. This paper introduces design and ergonomic assessment for remanufacturing workcell for light weight, hull shaped free-formed components. It demonstrates that the use of digital process simulation is a valuable tool and leads pathways towards establishing better workplaces where work related disorders are frequentely reported in such industries

Unified representation of fixtures: Clamping, locating and supporting elements in CNC manufacture

International audienceA CNC machining operation is the outcome of the application of the integrated capabilities of various resources within the CNC machining centre. Part fixtures, clamping and other location mechanisms are essential subsets of CNC machining resources. Today, various fixturing techniques and attachments available on the market allow manufacturers to enhance their production capability without buying expensive machine tools. This technology rich fixturing domain is detached while representing and exchanging machine tool resource information for making manufacturing decisions. The research work in this paper utilizes the STEP-NC compliant Unified Manufacturing Resource Model (UMRM) for representing fixtures in conjunction with the parent CNC machining centre. Thus UMRM is enhanced in this context to represent various fixtures such as universal vises, chucks, pallets, auxiliary rotary tables among others. The major contribution of this paper is the application of the extension of the UMRM approach for representing fixturing domain, which allows generic modelling of fixtures and loading devices in addition to machine workpiece and process modelling. This would enable the stage of automated process planning and manufacturing. The universal approach in representing resource information allows the data to be utilised for making a wide variety of manufacturing decisions