This study examines the use of graph centrality to identify critical components in assembly models, a method typically dominated by computationally intense analyses. By applying centrality measures to simulated assembly graphs, components were ranked to assess their criticality. These rankings were compared against Monte Carlo sensitivity analysis results. Preliminary findings indicate a promising correlation, suggesting graph centrality as a valuable tool in assembly analysis, enhancing efficiency and insight in critical component identification.

Model-Based Definition provides several benefits for communicating between engineering and other downstream stakeholders. Particularly, semantic PMI information included in 3D models benefits both CAM programming and inspection phases. However, the efficiency of generating CAM- and CAI codes automatically according to the semantic PMI information varies due to the compatibility of different systems. This paper focuses on the experiment that we made on inspecting three different parts with the Coordinate Measuring Machine (CMM). We compared four different programming methods and found that the efficiency of inspecting depends on the serial size of the parts. The completely automatic CAI-programming method does not necessarily produce the most effective CAI code compared to the competent human programmer. This is notable, especially in large series due to achieved cumulative time savings in the inspection of each part. With small series, fully automatic PMI method and human-assisted automatic PMIfp method provide significant benefits in the inspection process due to time savings in CAI-programming work.

The tolerancing of products for manufacturing is usually performed at the end of the design process and the responsibility of the designer. Although components are commonly tolerated to ensure functionality, time-based influences, like wear, that occur during operation, are often neglected. This could result in small amounts of scrap after production, but high quantities of failure during operation. To overcome this issue, this paper presents an approach to perform a multi-objective optimization considering tolerances based on a wear simulation. Thereby, mean shifts serve as optimization variables, while the aim of the optimization is to generate an optimal ratio of scrap to failure. In addition, the optimization results are interpreted and further options for the designer are presented. Moreover, the approach is exemplary applied to a use case.

The variation management and product quality processes are important tasks to guarantee the assemblability of the systems, the scrap reduction and to avoid delays on production and launching. The compound of activities in Geometric Dimensioning and Tolerancing (GD&T) are necessary, especially in the early design stages, to take into account variations of different nature and from different sources. In this paper, an approach for considering the loading conditions in a polyhedral-based approach in tolerancing design is presented. The load boundary conditions are represented as additional displacement restrictions in the deviation space. The restrictions imposed by the physical limits of a system, the ones coming from the loading conditions and the degrees of freedom (DoF) can be all described and represented with a single polyhedron operand. The approach is illustrated using a simplified 2-D model for both ideal and non-ideal geometry. A 3-D model describing an unilateral contact is presented as a case study using Skin Model Shapes. By taking into account geometrical form defects, external loads, and the kinematics of the system, its sensitivity to variations can be reduced even from early design stages.

The success of a company is directly linked to its economic objectives. One of the elementary objectives is to maximize profit by reducing the company's own costs in order to increase competitiveness in the market. State of the art is the function-oriented and unambiguous technical specification through the application of Geometrical Product Specifications (GPS). Linking costs related to the GPS system is currently only possible to a limited extent. This contribution presents an approach to quantify costs based on statistical tolerance analysis. The application is intended to determine the impact of a GPS-compliant specification in direct comparison to a non-compliant technical drawing by analyzing scrap rates. In this way, an assessment of the changes associated with the consistent application of the GPS system should be achieved. The results of the study show that a comparison is only possible to a certain degree due to the different characteristics. Based on this finding, an extended evaluation methodology is described.

The strive for design principles, qualitative and quantitative design tools, and product development methodologies that enable and support the design of robust products, that is products which are insensitive to noise and variation, is an ongoing challenge for both practitioners and academics. This paper reviews and classifies recent research efforts dedicated to robust design originating from the design society and carves out important challenges and potentials for future research. The main novelty of the paper can be found in the structured analysis and classification of recent robust design efforts as well as in the systematic elaboration of future research challenges, which seeks to stimulate a discussion on future tasks and challenges in robust design research.

In design engineering, the early consideration of tolerance chains contributes to robust design. For this, a link of design and tolerancing domains is essential. This paper presents a combination of the graph-based tolerancing approach and the Contact and Channel approach to link these domains. The combined approach is applied at a coinage machine. Here it provides detailed insights into state-dependent relations of embodiment and functions, which can improve robustness evaluation of the concept. This approach shows a possibility to bridge the gap between design and tolerancing domains.

To maintain functional tolerances of gear sets over their lifetime, especially in polymer-seel gear sets, the wear behaviour must be considered. The state of the art in wear modelling does not take the run-in behaviour of polymer-metal contacts into account. This results in oversizing of wear allowances in the stationary wear phase and undersizing in the run-in phase. Therefore, a modified wear model is presented in this paper. With this method the issues of over- and undersizing can be eliminated.

The method is then applied in a case study to show two things. Firstly, using the presented method the calculated necessary wear allowances were reduced by 30%. Secondly, the effect of surface structures on the wear behaviour was investigated. It is shown that the run-in process is not dependent on roughness in sliding direction, but on overall contact area. Thus, the state of the art, i.e. tolerating only the roughness in sliding direction, is insufficient. Considering the process-induced surface topology during design of gear sets can decrease run-in wear. Together with the optimised wear model, this allows wider manufacturing tolerances and thus lower costs during production.

Geometrical work piece deviations are unavoidable and directly affect the function and quality of technological products. Tolerance management is regarded as a crucial subtask of the development of technological products, because it ensures the function as well as a sufficient product quality while maintaining reasonable production costs. That means, that geometric tolerances as an essential part of the product description greatly affect the functional capability, manufacturability, mountability, verifiability and the costs of the final product. The research group FOR 2271 was founded to enable the computer-aided specification of tolerances, which meet the requirements of production, assembly, verification and function by close cooperation between the departments responsible for product design, assembly and metrology. The aim of this contribution is to determine the manufacturing process scatter as well as the measurement uncertainty and establish ways and means to include that information into efficient meta-models, ultimately enabling improved and accurate tolerance analyses.

Lightweight Design as an engineering domain is becoming more and more important in terms of sustainable mobility. Therefore, a large number of researchers is developing methods for utilisation of modern, but as well more complex materials with high lightweight potential. One subgroup of these materials are fibre-reinforced plastics (FRP). A lot of work is done supporting the design engineer in exploiting the structural and mechanical behaviour as good as possible. Whereas variations of laminate parameters, resulting from production, are poorly studied. Their impact especially on defined measures under load is of high importance, e.g. having a look on clearances in automotive industry. Because of the high complexity of FRP-parts, resulting from many laminate parameters, tolerancing is not an intuitive process. This is reflected in the fact that there is no defined procedure for tolerancing of FRP- parts. To support the design engineer the authors perform sensitivity analysis for simple loadcases to identify layers with a high importance on a defined measure. The results then are generalised to provide general guidelines to the design engineer.

Due to the varying environment conditions as well as the manufacturing induced deviations, the properties of products vary. In order to still meet the increasingly tightening of functional requirements, tolerancing as well as Robust Design practices became integral parts of the product development. However, despite the fact that the robustness of a product is mainly determined by its conceptual design in early design stages, these activities are usually carried out at the end of the design process. In order to overcome this shortcoming, this contribution shows a method that supports the selection of robust principal solutions and thus contributes to the design of product concepts, which are less sensitive to variations. The novelty lies in the adaption and combination of robust design criteria for the quantitative robustness evaluation in the conceptual design stage. First the product characteristics, which are relevant for the product robustness are determined on the basis of the function structure. By using an adopted VMEA and a newly developed evaluation matrix, this allows a thorough robustness evaluation of product concepts. The method is exemplary shown for a lifting table.

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 study of an X- ray shutter is carried out, whereby surrogate models are integrated in order to reduce the computing time.

The aim of this paper is to examine the current state of research on tolerance-induced costs in Germany. Through a literature research already existing approaches for the determination of costs related to tolerances during the specification of technical components are pointed out and possible approaches for the reduction of these costs are presented. In addition, the actuality of these approaches will be considered. One question that is supposed to be answered here is to what state of standard for the specification of components these approaches can be assigned to. On the other hand, it should be clarified whether the existing approaches are applicable to the currently valid standard system of the Geometrical Product Specification (GPS).

Can the economic efficiency of the specifications selected for tolerancing be determined in a technical drawing during the product development process in accordance with GPS on the basis of the current state of research?

Computer aided tolerancing (CAT) in the automobile industry is implemented by CAD tools. These tools analyze the manufacturability of complex assemblies with rigid single parts in an early stage to reduce the product development time and the cost for hardware prototypes. This paper proposes an approach to implement tolerance simulation for a compliant assembly, which includes manufacturing processes such as clinching, bolting and hemming by applying tolerance simulation tool. The fender- BIW system is simulated as a compliant–rigid system and the simulation model is applied to two production scenarios. The simulation results are compared with real measurement data, which demonstrates the efficacy of using simulation in early production as opposed to prototyping or other methods of design by showing the strong correlation between simulation results and as-built products.

Technological advances as well as novel manufacturing and design paradigms, such as industry 4.0 and digitalization, offer new opportunities for innovative products. However, they also increase the product complexity and cause new challenges in the production process. Therefore, agile production approaches are crucial. Tolerance compensation provides more flexibility in the production process, as demands on dimensional accuracy of the components are reduced. As a result, tolerance compensation also offers the possibility of reducing production costs without compromising product quality. Nevertheless, tolerance compensation is often considered a reactive intervention to reduce the number of out-of-spec parts a posteriori instead of including it in the early stages of Geometrical Variations Management. The contribution tackles this issue by characterizing and categorizing different methods of tolerance compensation as well as providing design guidelines for the application of tolerance compensation methods. This enables design engineers to select a suitable tolerance compensation method for different applications.