A parallel kinematic machine (PKM) topology can only give its best performance when its geometrical parameters are optimized. In this paper, dimensional synthesis of a newly developed PKM is presented for the first time. An optimization method is developed with the objective to maximize both workspace volume and global dexterity of the PKM. Results show that the method can effectively identify design parameter changes under different weighted objectives. The PKM with optimized dimensions has a large workspace to footprint ratio and a large well-conditioned workspace, hence justifies its suitability for large volume machining.

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Although new generation carbon fibre reinforced thermoplastic (CFRTP) such as carbon fibre reinforced polyetherketoneketone (CF/PEKK) is a promising sustainable alternative to the conventional thermoset CFRP, there is a lack of literature regarding its machining performance. This is the first study unveiling the hole wall and chip temperature evolution during drilling of thermoplastic CF/PEKK composite and the resulting material damages have been studied in detail. Through comparative study with CF/epoxy, the disparate drilling performance of the two composites has been uncovered, and the results were found to be closely related to the materials’ thermal/mechanical properties. Specifically, CF/PEKK produces continuous chips due to its excellent ductility and thermal sensitivity, whereas CF/epoxy produces segmented chips due to its brittle nature. CF/PEKK generates up to 40 N (50.5%) higher thrust force, 87.6 ℃ (98.9%) higher hole wall temperature and 61.1 ℃ (48.8 %) higher chip temperature than that of CF/epoxy. This has been correlated to the longer tool-chip contact length of CF/PEKK and its unique chip morphology. Despite the greater thrust force/temperature generation, CF/PEKK shows 55.7% lower delamination damage than CF/epoxy, and this is owning to its excellent interlaminar toughness. This study establishes a more in-depth understanding into the drilling performance of thermoplastic CF/PEKK and thermoset CF/epoxy and also provides guidance on the high performance manufacturing of next generation CFRPs.

Representing financial data streams in digital simulations to support data flow design for a future Digital Twin. Robotics and Computer-Integrated Manufacturing, 61, [101853].