Lipase-catalyzed ester formation in organic solvents an easy preparative resolution α-substituted cyclohexanols

The commercial preparation “lipase My” catalyses ester formation from an alcohol and a fatty acid in organic solvents. Preparative resolution of α-substituted cyclohexanols, including menthol, was achieved under these conditions.     

Toward a Hybrid-Trefftz element with a hole for elasto-plasticity?

The paper deals with the modelling of riveted assemblies for full-scale complete aircraft crashworthiness. Many comparisons between experiments and FE computations of bird impacts onto aluminium riveted panels have shown that macroscopic plastic strains were not sufficiently developed (and localised) in the riveted shell FE in the impact area. Consequently, FE models never succeed in initialising and propagating the rupture in the sheet metal plates and along rivet rows as shown by experiments, without calibrating the input data (especially the damage and failure properties of the riveted shell FE). To model the assembly correctly, it appears necessary to investigate on FE techniques such as Hybrid-Trefftz finite element method (H-T FEM). Indeed, perforated FE plates developed for elastic problems, based on a Hybrid-Trefftz formulation, have been found in the open literature. Our purpose is to find a way to extend this formulation so that the super-element can be used for crashworthiness. To reach this aim, the main features of an elastic Hybrid-Trefftz plate are presented and are then followed by a discussion on the possible extensions. Finally, the interpolation functions of the element are evaluated numerically.     

Image-Based Inertial Impact Test for Characterisation of Strain Rate Dependency of Ti6Al4V Titanium Alloy

Experimental Mechanics - In the present work Image-Based Inertial Impact (IBII) tests are performed on Ti6Al4V material. The IBII test uses an impact on the edge of the specimen to generate a short...