In the realm of manufacturing, characterising the mechanical properties of small and complex components has always posed a significant challenge. Conventional testing methods like uniaxial tensile testing often fall short due to the inability to create tensile coupons from these intricate parts. Recognising this limitation, our team, in collaboration with Spur, set out to utilise the novel PIP testing method on a small aluminium bicycle rim.

Challenges and Objectives Conventional mechanical testing techniques, such as uniaxial tensile testing, come with strict limitations when it comes to small and complex parts. The creation of tensile coupons from these components proves to be impossible in many cases, hindering accurate characterisation. Moreover, the production process itself can significantly alter the material properties, emphasising the need for post-production mechanical property analysis. Our team set out to obtain accurate mechanical testing data for a small extruded aluminium part, specifically an aluminium bicycle rim provided by Spur. PIP testing was posed as a potential solution to the current issues with testing due to the method’s unique ability to obtain critical data for small and complex components by testing directly on the parts themselves.

Materials and Measurements The study utilised a section of an aluminium bicycle rim provided by Spur. The extruded part exhibited an intricate cross-section design that maximised strength while minimising mass — a testament to the complexity of the component.

To measure the mechanical properties, an Indentation Plastometer was employed. The PIP test, which uses an accelerated inverse finite element method to infer accurate stress-strain curves from indentation test data, required minimal sample preparation and took only three minutes to complete. This method reduced the necessary sample volume by 99% compared to conventional tensile testing, which typically necessitates the creation of a full tensile coupon.

Results Our team successfully performed indentation tests on three faces of the extruded part, allowing for comprehensive stress-strain analysis. The PIP-inferred stress-strain behaviour exhibited similarities across all three indents. Notably, the material displayed a yield strength of approximately 270-280 MPa, with limited work hardening until failure.

Outcomes The application of PIP testing proved to be a game-changer, providing accurate mechanical data that conventional methods cannot obtain from small and complex components. Notably, the use of PIP testing significantly reduced the required sample volume and preparation, leading to faster turnaround times and cost savings.

This case study highlights the remarkable capabilities of PIP testing in obtaining accurate mechanical information from small and complex parts. With its ability to overcome the limitations of conventional testing methods, PIP testing emerges as a crucial tool for manufacturers seeking to optimise their production processes while gaining vital insights into the mechanical behaviour of their products. By embracing PIP testing, manufacturers can enhance the quality and reliability of small and intricate components.

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