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The cost reduction is one of the most spread strategy adopted by companies for guaranteeing profits in a competitive market. This paper presents an approach for the cost optimization of industrial electrical routings. The proposed optimization process consists of two levels: the arrangement of the cables within the cable trays and the 3D routing of the cable trays for connecting the modules of a product. The arrangement of the power and signal cables and the selection of the cable trays are carried out considering specific configuration rules. A genetic algorithm, coupled with the Hightower's algorithm, is used to solve the routing optimization problem. The proposed cost functions consider the raw materials and manufacturing/assembly operations. The optimization process has been used for optimizing a portion of the electric cable harness of a 43 MWe power plant with a size of 44 × 20 meters, and a total of 40,60 kilometers of cables. The optimization process let to a cost saving of about 15% compared to the design carried out with the traditional approach. Abbreviations:CTs: cable trays; CUi: hourly rate for the installation phase [€/hour]; CUrmtk: hourly rate for the k-th cost center used for transforming a semi-finished component [€/hour]; Cut: hourly rate for the test phase [€/hour]; CUtray: unitary cost of a cable tray [€]; DOE: design of experiment; GA: genetic algorithm [€]; Ic: installation cost [€]; If: installation factor [-]; PAc: cost for the preliminary analysis [€]; PAcp: percentage used for calculating the cost of the preliminary analysis [%]; RMc: cost of the raw material and relative transformation operations [€]; RMcci: cost of the i-th commercial component [€]; RMoc: percentage of the overhead costs related to the management of the raw material [%]; RMsc_scrapsj: cost of the scraps for the j-th semi-finished component [€]; RMscj: cost of the j-th semi-finished component [€]; RMtc: cost for transforming semi-finished components [€]; Tcl: commercial length of a straight cable tray [meter]; Tii,j: standard installation time for the i-th or j-th component [hour]; Tl: linear distance between two points of the wiring system that need to be connected [meter]; Trmtk: time for the k-th operation for transforming a semi-finished component [hour]; Ttk: standard test time for the k-th skid of the electrical system [hour].

This paper presents an approach for the product multi-objective optimization by associating the Response Surface Methodology (RSM) and the Design of Experiments (DoE) technique with the CAD/CAE/DfC integration. The goal of this study is to empirically identify the relationships existing between the design features and the product response (stress, strain, cost, etc.). This approach integrates three different levels of analysis: optimization problem definition, virtual prototyping and design optimization. The optimization problem definition concerns in choosing the design variables, setting constrains that have to be observed and goals that have to be achieved. The virtual analysis allows defining the principal parameterization of a geometric model and simulating the performance of each configuration, at a specific working condition, while evaluating the manufacturing cost and time. The proposed approach investigates the effect of the defined parameters and noise factor on the experimental results....

PMI annotations are widely used to support the Model Based Design within modern companies. In particular, the introduction of digital annotations marks the transition from the 2D drawings to the 3D representation in many manufacturing and design companies. However, today the implementation of the PMI technology presents some limits, such as the lack of functions to generate structure templates to be applied to similar CAD models. The proposed approach aims to overcome the limits of traditional tools which are not able to add a PMI annotation’s structure from one model to another one. The paper describes a method to reuse digital PMI annotations in a new model during the design phase, where the annotations are inherited from similar CAD documents. The proposed approach is based on two levels of geometric analysis: the searching of similar template models from an XML database, and the identification of the related geometric entities, which are used as associated objects for the definition of 3D annotations. The test case is focused on the automatic generation of PMI annotations for exhaust duct items used in oil & gas applications. The proposed tool has been developed within a software program called Duct Designer, which is used for the CAD automation of duct items. Particularly, the test case enhances the retrieval and reuse of sizing schemes from previous 3D models in order to obtain an automatic rebuilding of the geometric annotations.

Despite of the widespread of annotated 3D virtual models, it is still important to produce engineering drawings for a correct communication among the people of the design and manufacturing chain. Automatic drafting through meta drawing definitions, called Drafting Schemes, is proposed in this paper to save time when drawing becomes a repetitive task. The approach produces drafts with a predetermined content in terms of views arrangement and dimensioning strategy, and guarantees robust results to the variations of the input geometry. In fact, the geometrical entities referenced by the generated dimensions are retrieved through dedicated search algorithms based on recognition of geometric features of the input model.The approach has been implemented and tested on a family of gear motors showing feasibility and good results in terms of drafting time savings.

Current CAD systems have dedicated functionalities to model weld beads, but it is often cumbersome to use these systems. This study presents a method to analyze the geometry of assemblies of B-Rep models to automatically identify possible welds among the parts using prediction rules. Adjacent faces are detected, and Boolean operators on planar loops are used to identify bead paths. Beads are then split in homogeneous portions based on the topology of the connected parts. The main goals of this study are to increase the speed of the welding definition process and to benefit applications such as the cost estimation of steelwork products. Cost estimates are based on the shape, the length and the dimension of each weld bead. Some industrial examples are presented to show the benefits in terms of time savings and accuracy to the estimation process.

Optical Reverse Engineering systems are evermore used to check dimensional and shape conformity of manufactured components; their main advantage is the short acquisition time. Dedicated CAD software tools allow comparing the acquired data (clouds of points) with the 3D CAD model. Generally, they support the automatic global shape measurement; from the designer viewpoint this is not sufficient. The desired functional behavior of component is respected only when specific geometrical tolerances are verified. Our aim is the definition of methods to automate this last control process using Full of Information (FoI) CAD models. We define them as 3D model containing tolerance attributes and methods to check them. They allow comparing the toleranced features with the corresponding parts of point clouds. The present paper describes the approach and the developed method for datum identification usable for orientation and localization geometrical tolerances control.

Patients affected by serious foot pathologies often require special orthotics to stand and walk correctly. Skilled operators obtain such insoles on the basis of manual procedures and following the prescriptions of orthopaedic technicians. The process is handicraft and time consuming. The paper presents a virtual prototyping approach which is based on dedicated foot scanners, CAD-based design tool and milling machines to obtain the bespoke footwear orthotics. The major contribution is a geometric procedure to design complex insole shapes starting from the foot scan and highly customized shoe lasts which are required in case of important deformities.The approach has been tested on several patients thanks to the collaboration with a partner insole producer and some orthopaedic centers. Patients have generally reported positive feedbacks on the comfort and functionality of the insoles.