A Novel Model-Based Approach for the Design of Scalable Crimp Connectors for SMA Wire-Based Actuators

Abstract While SMA wire-based actuators hold great potential across a range of industries, including medical, automotive, and consumer goods, the system integration of these wires poses a significant challenge, particularly in the context of fully automated mass production. Currently in all known industrial applications, only crimp or splice connectors are employed to connect the wire to its system environment. However, there is no standardized method for systematically designing crimp connectors while considering application-specific requirements. Furthermore, the property rights situation becomes more restrictive, as the protection claim of an expanding number of patents extends beyond the technical design of SMA actuators to their production processes in detail. Nevertheless, crucial process characteristics, particular those related to a crimping process, are undisclosed. In addition, since these documents usually describe specific products, transferring them to other applications remains difficult. To address these challenges, the fundamental connection mechanisms of crimp connectors will be analyzed, and an easily scalable crimping concept will be developed, considering existing intellectual property rights. This crimping concept is then characterized by a parameter study using the Design of Experiments method and static pull-out tests to identify crucial influencing factors and their interactions and to be able to build a mathematical model that maps the parameter- dependent pull-out strength of the connection. Based on the theoretical analysis of the fundamental connection mechanisms and the practical insights into influences and interactions affecting the static pull-out strength of the crimp connection, a systematic method will be devised to facilitate the design of model-based, cycle-resistant crimp connections in accordance with application-specific requirements.