GOING BEYOND EYE LIMITS: FASTER OBSERVATION TO GAIN AN INSIGHT INTO FRACTURE MECHANICS

Nowadays, the suitability of the incorporation of new technologies to learning is out of doubt. Nevertheless, certain reluctances arise in the academic community concerning the use of research equipment for student learning activities. Some of the claimed reasons for not to employ research facilities and research methods for engineering education are: vulnerability of non commercial equipment when used by inexperienced operators; high costs associated to equipment acquisition and operation; relatively long preparation times and operation times required to obtain valuable outcomes. Nevertheless, throughout a correct approach it is possible to overcome most of these difficulties and to successfully utilize research resources as practical equipment for students learning, already in the first engineering courses. This educational use allows amortizing the elevated investments commonly required for the acquisition of research equipment. Moreover, the students’ knowledge in the newest technologies is considered an important contribution to modernize industrial networks; the consolidation of research activities in private institutions is a very important aspect in countries with low technological activity.

From the academic point of view, the use of advanced equipment acts as motivating agent for both students and teachers. The incorporation of research facilities to practical learning promotes not only an expansion and an enhancement of the student understanding, but also the optimization of the teachers’ knowledge in their role as learning conductors. In fact, we should not forget that the emerging profile of teachers in the European Universities mainly presents aspects as educator and researcher. This work presents the application of high speed video acquisition to fracture analysis as practical learning activity for mechanical engineering and material engineering students. High speed video acquisition is an experimental technique employed at research level to acquire fundamental information from fast phenomena. Between the required equipment, ultrahigh speed C-MOS sensors are employed to obtain image acquisitions with shutter times in the microsecond range (approximately 20000 times shorter than human eye resolution). Complementary flash lamps even provide shorter lighting pulses down to few nanoseconds. Fracture mechanics is a branch learned in the framework of advanced stress analysis, in the last years of the engineering studies. The common approach includes mathematical modelling of fracture mechanics, crack growth and prediction of catastrophic failure; the practical activities limit to static load experiments and do not cover the observation of fracture under fast load conditions. The use of high speed video acquisition constitutes a step forward for the fracture mechanics learning. This work presents and discusses the design and development of this practical learning activity assisted by research technology.