Tag Archives: simulation

Model credibility

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Last week I spoke at the annual conference of the Associazione Italiana per ‘Analisi dell Sollecitazioni in Vicenza, Italy on the role of experimental mechanics in the validation of computational models used in engineering simulations.  We discussed the conflict between reducing cost and energy consumption and increasing performance and reliability of engineering machines and vehicles.  Generally, the former implies using less material more efficiently, while the latter tends to require the use of more material.  Engineers resolve this conflict by using computational models when optimising designs to simulate engineering behaviour.  The development of elegant and successful designs requires a high level of credibility in the models.  This credibility can be established by comparing the results from models with those from specially-conducted experiments; a process that is known as ‘validation’.

Two Earths

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An enormous amount of time and money are expended on developing engineering simulations and establishing their credibility using information from experiments.  You could ask: why? After all for structural reliability we could just use more or stronger material to avoid unexpected failures.  One answer is that more or stronger material either costs more and, or weigh more.  The additional weight requires the use of more resources, including more energy for manufacturing and operation of engineering machines, structures and systems.  Engineers have a responsibility to support a shift by society to use less resources while achieving the same standard of living, because to provide the same standard of living enjoyed by the average European (North American) citizen to everyone on this planet would require the resources of two (four) more earths using our current technology*.  The latest pictures from the Curiosity Rover on Mars suggest that our nearest neighbour isn’t going to be of much use to us.

*Based on average ecological footprint of 2.5 acres per person in the developing world, 13.5 acres per person in the UK and 24 acres per person in the USA.  For more on this theme see Edward O. Wilson, ‘The Future of Life’, The 2001 John H. Chafee Memorial Lecture.

[Picture Credit: NASA Goddard Space Flight Center Image by Reto Stöckli (land surface, shallow water, clouds). Enhancements by Robert Simmon (ocean color, compositing, 3D globes, animation). Data and technical support: MODIS Land Group; MODIS Science Data Support Team; MODIS Atmosphere Group; MODIS Ocean Group Additional data: USGS EROS Data Center (topography); USGS Terrestrial Remote Sensing Flagstaff Field Center (Antarctica); Defense Meteorological Satellite Program (city lights).]