• Raul Ochoa Cabrero

Student thesis: Master of Philosophy


Biological experimentation has many obstacles which include: resource limitations, unavailability of materials, manufacturing complexities, time scale difficulties and, ethical compliance issues. As such, any approach that resolves all or some of these issues is of some interest to the bio-community. The aim of this work is the application of the recently discovered concept of finite similitude as a novel scaling approach for the design of scaled biomechanical experiments. Finite similitude exists when the physics on scaled spaces is described by proportional transport equations and demonstrated in this thesis is how the concept can be applied to scaled-biomechanical experimentation supported with analysis using a commercial finite element package and validated by means of an image correlation software. The study of isotropic scaling of synthetic bones leads to the selection of 3D printed materials for the small-scale, trial-space materials. The 3D-printed material conforming to the theory is analysed in finite element models of a simple geometry (cylinder) and in a femur geometry undergoing compression, tension, torsion and bending tests to assess the efficacy of the approach. The results show similar strain patterns in the surface for the cylinder with a maximum difference of less than 10% for all the tests and for the femur geometry a maximum difference of less than 4% for all the tests. Finally, the trial-space, physical-trial experimentation using 3D printed materials for compression and bending testing provides a good agreement in a Bland Altman statistical analysis since the limits of agreement are below the accuracy of the image correlation software providing good supporting evidence for the practicality of the approach.
Date of Award31 Dec 2018
Original languageEnglish
Awarding Institution
  • The University of Manchester
SupervisorKeith Davey (Supervisor) & M.T. Alonso Rasgado (Supervisor)


  • Biomechanics
  • Experimental Design
  • Scaling Theory
  • Similitude

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