title: Bending properties of a macroalga: Adaptation of Peirce's cantilever test for in situ measurements of Laminaria digitata (Laminariaceae).
abstract: • Premise of the study: The mechanical properties of a plant are key variables governing the interaction between the plant and its environment. Thus, measuring variables such as the flexural rigidity (bending) of a plant element is necessary to understand and predict the plant-flow interaction. However, plant elements such as macrophyte blades can be relatively thin and flexible, thus difficult to characterize. Different adaptations of the classical 3-point bending tests can also affect the interpretation of the flexural rigidity of an element. A simple, robust, method is newly applied to a biomaterial and validated here as an alternative to measure flexural rigidity of thin, flexible plant elements.• Methods: Based on a bending test procedure developed for the textile industry, an apparatus for in-situ measurements was developed and compared with other normalized methods, then used in a field test on the blade of a marine macroalga (Laminaria digitata) to assess its suitability to measure the bending modulus of a biomaterial.• Key results: Results of the presented method on selected surrogate materials agree with a normalized cantilever method (ISO 9073-7:1998) and 3-point bending test (ISO 178:2010). Values determined for the bending moduli for blades of L. digitaria were in the typical range for algal material. The range of validity of the method is discussed.• Conclusion: By validating this method with existing norms, this study suggests a better approach to measure bending properties of different biomaterials in the field compared with more traditional bending tests and opens new possibilities.
authors.affiliation: Department of Marine Technology, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway.
authors.forename: Pierre-Yves T
authors.initials: PY
authors.lastname: Henry
mesh_terms: D001696:Biomechanical Phenomena; D055119:Elastic Modulus; D044423:Kelp; D007795:Laminaria; D008422:Materials Testing; D013314:Stress, Mechanical
keywords: Laminaria digitata; Laminariaceae; bending modulus; bending test; biomaterial; biomechanics; flexural rigidity; macroalga