Featured Application: Acoustic design and characterization of sandwich panels.Abstract: Sandwich structures are manufactured using multiple combinations of materials for core and laminates. The real performances are influenced by variability in the composing layers and even by the uncertainties introduced while bonding them together. Therefore, experimental tests are usually the preferred way to assess the most important parameters required to develop and to characterize the product, the main downsides lying in their cost and time consumption. This work explores a practical application of the wave propagation approach by means of a case study, in which some significant properties of an aluminum honeycomb panel are obtained starting from simple vibro-acoustic tests carried out on beam specimens. After determining the frequency-dependent bending stiffness function, the sound transmission loss is predicted and compared with the experimental results obtained in sound transmission suites. The same vibro-acoustic tests are used to estimate the core shear modulus. Finally, a parametric study is proposed to show how this technique can be effectively used in the early design stage, when producing physical samples is often impossible due to time and money constraints. The method proved to be a reliable and powerful tool in all the tested applications, providing good results with limited computational effort.
This work presents the development of an integrated framework and related tools for innovation and improvement in the teaching of Technical Drawing. This framework is based on the “Technical Drawing Evaluation Grid—TDEG.” This grid is currently used, by the authors, for the definition and the development of different kinds of tools for supporting both teaching and learning and for the evaluation of Technical Drawing and engineering graphics topics knowledge in general. In particular, this paper focuses on the problems related to knowledge evaluation and assessment of Technical Drawing using online tests. Then, the LaMoo project which is a tool under development for the structured construction of questions for online tests in Moodle environment is presented.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.