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Snap fits are crucial in automotive applications for rapid assembly and disassembly of mating components, eliminating the need for fasteners. This study aims to focus on designing and analyzing serviceable cantilever fit snap connections used in automobile plastic components. Snap fits are classified into permanent and semi-permanent fittings, with permanent fittings having a snap clipping angle between 0° and 5° and semi-permanent fittings having a clipping angle between 15° and 45°. Polypropylene random copolymer is chosen for its exceptional fatigue resistance and elasticity.

The design process includes determining dimensions, computing assembly, disassembly pressures and creating three-dimensional computer-aided design models. Finite element analysis (FEA) is used to evaluate the snap-fit mechanism’s stress, deformation and general functionality in operational scenarios.

The study develops a modified snap-fit mechanism with decreased bending stress and enhanced mating force optimization. The maximum bending stress during assembly is 16.80 MPa, requiring a mating force of 7.58 N, while during disassembly, it is 37.3 MPa, requiring a mating force of 16.85 N. The optimized parameters significantly improve the performance and dependability of the snap-fit mechanism. The results emphasize the need of taking into account both the assembly and disassembly processes in snap-fit design, because the research demonstrates greater forces during disassembly. The approach developed integrates FEA and design for assembly (DFA) concepts to provide a solution for improving the efficiency and reliability of snap-fit connectors in automotive applications.

The research paper’s distinctiveness comes from the fact that it presents a thorough and realistic viewpoint on snap-fit design, emphasizes material selection, incorporates DFA principles and emphasizes the specific requirements of both assembly and disassembly operations. These discoveries may enhance the efficiency, reliability and sustainability of snap-fit connections in plastic automobile parts and beyond. In conclusion, the idea that disassembly needs to be done with a lot more force than installation in a snap-fit design can have a good effect on buzz, squeak and rattle and noise, vibration and harshness characteristics in automobiles.

The purpose of this paper is to investigate the effects of different shape memory polymer based snap‐fits in terms of disassembly time and reusability.

In total, six different sets of snap‐fits were designed and manufactured. Each set of snap‐fits was tested ten times in a testing device for disassembly time. The stress caused by training process is simulated and analyzed.

One of the designs shows shortest average disassembly time, lowest standard deviation, and lowest stress. However, the overall reusability of the snap‐fits is not good enough for industrial use.

The paper tests the Veritex shape memory polymer sheets manufactured by CRG Industries LLC. The reusability has been analyzed based on the stress caused by the training process.

This first part of a comprehensive six‐part series of articles on integral attachment using snap‐fit features familiarizes the reader with the key terms relating to the subject. Every area of study and practice must have associated with it a language to express objects, actions, and ideas. To understand any subject, understanding the language is essential. Developing clear, concise, unambiguous definitions of key terms is a tedious but necessary and critical first step to promoting understanding by allowing effective and efficient communication. These terms and definitions have been carefully compiled and thoughtfully refined from a broad industrial base, published literature, and university‐based research. They are the beginning of a lexicon for the embryonic but promising technology of integral attachment using snap‐fit features.

This paper aims to address the development and implementation of “AltPrint,” a slicing algorithm based on a new filling process planning from a variation in the deposited material geometry. AltPrint enables changes in the extruded material flow toward local variations in stiffness. The technical feasibility evaluation was conducted experimentally by fused filament fabrication (FFF) process of snap-fit subjected to a mechanical cyclical test.

The methodology is based on the estimation of the parameter E from the mathematical relationships among the variation of the material in the material flow, nozzle geometry and extrusion parameters. Calibration, validation and analysis of the printed specimens were divided into two moments, of which the first refers to the material responses (flexural and dynamic mechanical analysis) and the second involves the analysis of the printed components with localized flow properties (for estimating the response to cyclic loading). Finite element analysis assisted in the comparison of two snap-fit geometries, one traditional and one generated by AltPrint. Finally, three examples of compliant mechanisms were developed to demonstrate the potential of the algorithm in the generation of functional prototypes.

The contribution of AltPrint is the variable fill width integrated with the slicing software that varies the print parameters in different regions of the object. The alternative extrusion method based on material rate variation was conceived as an “open software” available in GitHub platform, hence, open manufacturing with initial focus on desktop 3D printer based on FFF. The slicing method provides deposited variable-width segments in an organized and replicable filling strategy, resulting in mechanical properties variations in specific regions of a part. It was implemented and evaluated experimentally and indicated potential applications in parts manufactured by the additive process based on extrusion, which requires local flexibilities.

This paper presents a new alternative method for application in an open additive manufacturing context, specifically for additive extrusion techniques that enable local variations in the material flow. Its potential for manufacturing functional parts, which require flexibility due to cyclic loading, was demonstrated by fabrication and experimental evaluations of parts made in acrylonitrile butadiene styrene filament. The changes proposed by AltPrint enable geometric modifications in the response of the printed parts. The proposed slicing and filling control of parameters is inserted in a context of design for additive manufacturing and shows great potential in the area of product design.

The third part of a comprehensive six‐part series on a promising and growing approach to mechanical attachment amenable to automation. Integral snap‐fit attachment design has traditionally focused almost exclusively on the individual features that actually accomplish locking between parts of an assembly (e.g. cantilever hooks, bayonet‐fingers, compressive hooks, traps, and others). The placement and orientation of features that facilitate or enhance engagement or eliminate unwanted translation, rotation or vibration, i.e. locating features and enhancements, are rarely considered. Here, describes integral features classified as locks, locators or enhancements. More importantly, presents a systematic six‐step approach or methodology to guide designers at the higher, attachment or conceptual design level (as opposed to lower, feature or detail design level).

This second of a six‐part series presents a hierarchical scheme for classifying integral snap‐fits at the attachment level, bringing great order to where there appeared to be chaos. The scheme is then used to enumerate all possible design options. The proliferation of plastic parts, and the ability to mould such parts of great complexity at little cost penalty, has resulted in the growing use of integral attachment in the form of snap‐fit features in designs. Heretofore, the great diversity of part geometry and integral snap‐fit features has made it appear that design possibilities may be unbounded, and that attempts at optimization might be intractable. The result shows that options can quickly be reduced to a small enough number to allow designers to compare every possibility, thereby making true optimization a practical reality. As such, the scheme guides new designers and validates choices for experienced designers in ways never before possible.

Suggests that, without question, while every step in a systematic approach to the design of parts for assembly using integral snap‐fit features is important, none is more important than selecting locking features. After all, it is these features that hold the assembly together. While quite different in appearance and details of their operation, all integral locking features comprise a latch and a catch component to create a locking pair. Proper, no less optimum, function requires that such locking pairs be selected using a systematic approach. Presents that approach as a six‐step methodology, but first, defines and describes latch and catch components, bringing order to their apparent boundless variety. Demonstrates the utility of the methodology with a real‐life case study.

This fifth part of a comprehensive six‐part series of articles presents a systematic procedure for formalising the generation of alternative concepts for a particular design employing integral snap‐fit attachments. With the procedure, the alternatives generated are representative of the entire pertinent design space, since they include alternative attachment interface geometries, assembly procedures, attachment features, and constraint options for a particular application. The procedure is easy to use, effective and efficient, and results in a number of alternatives which are sufficient to represent the entire pertinent design space, but not so large as to preclude selection of a best concept using an optimisation method.

Smart materials (SMs) have the potential for facilitating active disassembly (AD). Select SMs are used in the design of devices to aid product disassembly. The purpose of this paper is to compare different AD approaches and highlight future work and potential.

This work is a survey of the collated AD research employing only Smart and “made Smart” materials work from various published work in the field from companies and academia since its original invention. The introduction gives general discussion of AD with cost implications and how the technology could offer very lean dismantling. An overview of the history of the work is given with the context of the implications for the need for a technology like AD to retain critical materials.

Besides a survey to date, comparisons were made of each AD technology application highlighting advantages and challenges. Comparisons were also made prior to this in alternative disassembly strategies to give context to the potential usefulness of the technology.

Only AD with SMs or “made Smart” were highlighted with some considerations for potential candidates.

A survey of AD work only employing SMs and “made‐Smart” materials to date. Comparisons of each AD application were made highlighting advantages and challenges. Comparisons were made between AD and alternative disassembly strategies to give context to the potential usefulness of the technology. The conclusion included an overview of work with consideration for future work. A candidate technology with the most potential was discussed.