USE OF MODELS IN STRUCTURAL LEARNING: AN HISTORICAL REVIEW AND A PROPOSAL OF NEW STRATEGIES
This article describes a new approach to trials in models, to supplement architects’ and engineers’ training in structural theory and mechanics. To this end a wide-ranging revision was undertaken of the results of model use in teaching structural mechanics.
Ever since 1947, when A. J. S. Pippard described a structured way of using trials in teaching models, they have been used to supplement theoretical classes and practical exercises in teaching structural mechanics. They are now completely accepted as a useful way of improving the understanding of the concepts involved. Trials using models are now accompanied with computer tools which permit trial result simulation and often allow students to interact with them by modifying conditions, running a large number of trials in a single model.
As Brohn shows, bringing model studies into classes has not prevented many architecture and engineering graduates from failing to achieve a suitable level of understanding of structural behaviour. One of the skills these graduates should acquire is that of being able to define the most suitable analytical model for each case. For this it is necessary to understand structural behaviour, while also being able to synthesise and produce an analytical model that fits each case, before finally evaluating the results of the same.
Students also have to familiarise themselves with available computerised analytical methods, with how to create models and also how to evaluate findings. The proposed procedure therefore supplements the use of trials in models with the work of numerical modelling. Model trial instrumentation and analysis are complemented by use of the ARAMIS deformation optical measuring system. This makes it possible to measure displacement fields in models extremely precisely, and to process the results of this. This produces displacement fields and stress distributions in models subjected to trials, and these are used to verify the results of analysis using numerical models.
The article describes the tasks which students have to perform for a given problem: they have to express and construct the physical model, while also creating a numerical model. Analysis of the latter will predict the results of the trial. The trial is then performed in the model, and the results of this are compared with those of the previous analysis. This study may lead to suggestions for the improvement of physical and numerical models. Finally, a short report will describe the tasks performed and relevant conclusions. It will also contain a sufficiently exact description of the project studied for it to be constructed. With this, students will have used tools that are habitually used in professional practice to resolve an original problem. Although this model is intended for students in the final year of their architecture degree, it may also be used for structural engineering students.