How can Computer Aided Tolerancing Support Closed Loop Tolerance Engineering? (original) (raw)
Related papers
CAD-based environment to bridge the gap between product design and tolerance control
Precision Engineering, 2010
Mechanical product quality is strongly influenced by the respect of Geometrical Tolerances (GT). On the other hand, competitiveness forces companies to improve their productivity making the tolerance verification process faster and faster and more flexible. Component control by 3D full field optical digitizing systems and specific CAD-based (Computer Aided Design) inspection software tools are important steps forward for the achievement of the above-mentioned goals. However, the adoption of these solutions in industry is minimal. This may be due both to technological factors, i.e. poor systems usability, and organizing factors, i.e. clear separation between design department and quality control department. In this context, our research aims at developing a new easy to use CAD-based tool for simulating, driving and optimizing the GT inspection process. Once a component has been digitized, the developed software system automatically realizes the tolerances virtual control. Hence, the designer can prescribe tolerances, pilot the measurement system and verify the component conformity. The implemented tool is based on Full of Information (FoI) CAD models, which contain tolerance data, linked to a knowledge database, where measurement strategies and verification rules are stored. A computation engine calculates the measurement paths and performs the tolerances verification. The prototypal system has been tested on different real cases. Experimental results showed high performances in terms of timesaving and robustness.
Proceedings of the Design Society: International Conference on Engineering Design, 2019
To meet rising customer requirements, increasingly complex products have to be virtually validated. To achieve this within the framework of virtual product development, a wide range of aspects has to be taken into account. In this context, tolerance analysis has established itself as a proven tool to evaluate the consequences of geometric part deviations on geometric product characteristics. Existing approaches, however, do not sufficiently take into account production-specific deviations, leading to time-consuming iterations during the product development process. Therefore, the focus of this contribution is on process-oriented interdisciplinary tolerance management that allows the integration of manufacturing simulations into the tolerance analysis. In contrast to the conventional approach, this novel methodology allows to avoid unnecessary iterations in the context of product development and validation. Following the presentation of the novel procedure, the application on a case ...
Integration of tolerances in the mechanical product process: Assembly with defects modelling
2013
a. Mechanical Engineering Laboratory, National Engineering School of Monastir, Monastir University, Av. Ibn Eljazzar, 5019 Monastir, Tunisia. a, b. LIPPS, ETS, 1100, Notre-Dame Ouest, Montreal, H3C1K3, Quebec, Canada. Borhen.louhichi@etsmtl.ca, abdelmajid.benamara@enim.rnu.tn Abstract: The part and assembly requirements are specified by the tolerances. In the Digital Mock-Up (DMU), the product is designed on nominal configuration and the tolerances are formally allocated to the CAD model. Thus, the impacts of the tolerance stack-up on the advanced phase of the product design (Dynamic computation, F.E Analysis...) are neglected. The DMU improvement requires the tolerance integration in CAD model. A developed model allows obtaining the components with defects according to dimensional and geometrical tolerances specified in the nominal model. In CAD model, the assembly of the components with dimensional and geometrical defects requires the updating of the assembly mating constraints. T...
A Geometric Model for Tolerance Analysis with Manufacturing Signature and Operating Conditions
International Journal of Manufacturing, Materials, and Mechanical Engineering, 2019
In this work, a geometric model for tolerance analysis has been carried out. Geometric reasoning has been implemented in the model to simulate the manufacturing process and, then, the assembly sequence. The proposed geometric model has been applied to a case study consisting of two circular profiles due to the turning process, and a hollow rectangular box. The two circular profiles have been assembled inside the box by considering the gravity, and the friction among the parts and the actual points of contact with and without using the manufacturing signature. Matlab® software has been used to implement the geometric model for tolerance analysis. The results have been compared with those obtained by using a literature model with and without considering the manufacturing signature. This work aims to be a first step towards the integration of the design and the manufacturing in a concurrent engineering approach.
A Comparative Study on Tolerance Analysis Approaches
Robust product designs are characterized by their insensitivity to disturbances and noise, such as geometric part deviations, which are inevitably observed on every manufactured workpiece. These observed deviations are covered by the axioms of manufacturing imprecision and measurement uncertainty, which convey the concepts of variability and uncertainty as fundamental aspects of robust design. In order to ensure the product function though the presence of these geometric part deviations without building physical artefacts, tolerance simulations are employed in the context of computer-aided tolerancing. Motivated by the shortcomings of existing tools, the concept of Skin Model Shapes has been developed as a novel paradigm for the computer-aided tolerance analysis. This paper presents a comparative study on the standard procedure for the tolerance analysis employing proprietary CAT tools and the tolerance simulation based on Skin Model Shapes. For this purpose, two exemplary study cases are highlighted. Based on the comparisons, general remarks on the use of CAT tools in the context of tolerance analysis and robust design are derived.
A graph-based method and a software tool for interactive tolerance specification
Procedia CIRP, 2018
In today's business environment, the trend towards more product variety and customization is unbroken. Due to this development, the need of agile and reconfigurable production systems emerged to cope with various products and product families. To design and optimize production systems as well as to choose the optimal product matches, product analysis methods are needed. Indeed, most of the known methods aim to analyze a product or one product family on the physical level. Different product families, however, may differ largely in terms of the number and nature of components. This fact impedes an efficient comparison and choice of appropriate product family combinations for the production system. A new methodology is proposed to analyze existing products in view of their functional and physical architecture. The aim is to cluster these products in new assembly oriented product families for the optimization of existing assembly lines and the creation of future reconfigurable assembly systems. Based on Datum Flow Chain, the physical structure of the products is analyzed. Functional subassemblies are identified, and a functional analysis is performed. Moreover, a hybrid functional and physical architecture graph (HyFPAG) is the output which depicts the similarity between product families by providing design support to both, production system planners and product designers. An illustrative example of a nail-clipper is used to explain the proposed methodology. An industrial case study on two product families of steering columns of thyssenkrupp Presta France is then carried out to give a first industrial evaluation of the proposed approach.
Concurrent Conceptual Evaluation of Tolerances' Synthesis in Mechanical Design
Concurrent Engineering, 2011
Concerning with the global competitive environment and the impact of collaborative engineering environments on Small and Medium-sized Enterprises (SMEs), it is now necessary the development of new models and tools that can keep helping the designers and engineers in the decision-making processes related to the product design lifecycle. The tolerance synthesis purpose is to provide a rational basis for assigning tolerances to dimensions, and it has become an important subject in the product design process. The aim of this research work is to present an approach to support a concurrent conceptual tolerance synthesis evaluation process in a mechanical design within a collaborative engineering environment context, e.g. Virtual Enterprise. The reference model proposed was developed and refined through a set of mechanical design study cases. The analysis and reflections of the study case presented in this manuscript are described in detail to show an example of how the different study cases were used to develop an understanding of how the reference model proposed can stimulated the conceptual synthesis evaluation of tolerances in the product design process.
The characterization and specification of functional requirements and geometric tolerances in design
Journal of Engineering Design, 2006
In the process of mechanical design, tolerances are of crucial importance because decisions related to tolerances can have a decisive influence in terms of the product cost and quality. At present, there are numerous approaches and investigations related to the analysis and/or synthesis of tolerances and the modelling of assemblies. In this article, we look at the basic essentials required to deal correctly with the functional requirements and the geometric tolerances at the specification stage of the design process, in such a way as to guarantee the subsequent computer-aided tolerance synthesis at the basic and detail design stages. To achieve this aim, we developed an experience-based method. Applying this method to a set of real cases provided by the Industrial Equipment Design Centre at the Polytechnical University of Catalonia has enabled us to adjust the method to suit the application. The objectives proposed in this work are reached by the obtained results through applying the method.
Taking into account the global competitive environment and the impact of collaborative engineering environments on Small and Medium-sized Enterprises, it has now become necessary to develop new models and tools that can keep helping the designers and engineers in the decision-making processes related to the product design lifecycle. The tolerance synthesis purpose is to provide a rational basis for assigning tolerances to dimensions, and it has become an important subject in the product design process. The aim of this research work is to present an approach to support a concurrent conceptual tolerance synthesis evaluation process in a mechanical design within a collaborative engineering environment context, for example, Virtual Enterprise. The reference model proposed was developed and refined through a set of mechanical design study cases. The analysis and reflections of the study case presented in this manuscript are described in detail to show an example of how the different study cases were used to develop an understanding of how the reference model proposed can stimulate the conceptual synthesis evaluation of tolerances in the product design process.