Search

In an effort to develop thermoplastic composite tubes for helicopter landing gear applications, the mechanical behavior of straight tubes subjected to bending has been studied and presented here. It was found that interlaminar normal stresses of large values exist between layers located under the loading point. This can cause delamination between different layers at location under the loading point. The stiffness of the tube along the circumferential direction is important to prevent inward deformation under the load point, which can lead to buckling and sudden load drop. The absorption of energy upon fracture depends on the strategic placement of layers having different strain limits at proper locations along the thickness direction. © The Author(s), 2011.

A new martensitic ODS alloy (nominal composition Fe-9Cr-1W-0.2Ti-0.3Y 2O3) has recently been developed at CEA Saclay to achieve the goals defined for GEN IV reactors. The aim of this paper is to present the main challenges involved in the manufacturing of 9Cr-ODS cladding tubes. Internal stresses have been measured as a function of the thermo-mechanical treatments. Control of microstructural evolutions by means of phase transformation and appropriate cooling rates appears to be critical to obtain favorable softened structure which can be further processed for cold working. The final cladding tubes present remarkable mechanical properties with tensile strength higher than 350 MPa at 750 C in both longitudinal and circumferential directions. © 2013 Elsevier B.V. All rights reserved.