36 : Computational mechanics for engineers

Incontournable, la mécanique numérique s’insère aujourd’hui dans l’ensemble de la chaîne de conception rapide des produits fabriqués par l’industrie. S’appuyant sur les outils de modélisation géométrique et de visualisation, et intégrant les outils de simulation et d’optimisation, elle réduit les délais de conception, limite les erreurs et s’insère dans l’esprit du développement durable en aidant à concevoir des produits de plus en plus respectueux de l’environnement.

36 : Computational mechanics for engineers

An era of optimization

The sheer power of modern computers and availability of modelling tools which have become more and more reliable have led to the development of optimization software packages. The corporate world is full of more or less specialized demands, converging on the purpose of reducing production time, costs and improving product quality.

The list of intrinsic qualities expected of a new industrial product - silent, comfortable, light, clean, economical, rapid, accurate, safer, aesthetic ... is much longer than it was before. And, to comply with applicable standards, and consumer expectations can almost become a nightmare for system designers. And only one word fits the dilemma - o p t i m i z e!

For an engineering designing a car, the safety factors must be maximized, cost factors minimized (in production, design, utilization ...), and comfort must be maximized while lowering fuel consumption ... and the data related to the problem appears as a long list of constraints and objectives to be satisfied. "The main difficulty", says Hossein Shakourzadeh, scientific advisor with Altair, a company specialized in development of modelling software packages, "is to describe the optimization target precisely".

Road and airborne software

One question: how are you supposed to define "comfort"? Another: what must be taken into account when estimating costs? There are many questions and no really simple answers. And the latter depend in the solutions chosen for the new product envisioned. In order to assist the engineers, the professional software editors are now proposing a fairly wide range of optimization tools...

"We have to come up with solutions that meet the needs of all our customers, whether they build cars or planes", underlines Hossein Shakourzadeh. In many instances, different problems can be solved using the same tools. Thus software to meet the greatest number of needs was developed, and by changing the parameters, they can be used in a maximum number of situations.

Increasingly specialised modules

Over and above 'parametrable', generic tools, which are the closed shop domain of research engineers, we see more and more specialized modules being developed to implement optimization protocols for highly specific situations. For example, the Squeak and Rattle Director from Altair aims at minimizing the friction noise and 'squeaks' from various pieces of equipment and which can change through time. A typical example here is the car dashboard, but the tool used is not just restricted to this particular case.

"The software used complies with a demand from the industrialists to save time when designing parts and it transfers certain skills to the software editor", underlines Hossein Shakourzadeh. The engineer invited to design a dashboard does not have to be an optimization technique specialist at the same time - and hence he/she can concentrate on the job at hand - dashboard design.

The use of optimization packages began in the 1990s, and rely on improvement of previous models and tools. The attractiveness of the new tools stems in fact from the desire expressed by the industrialists to reduce design time, also from the economic race that forces them to constantly renew their offer with new products. Another important factor is the notable increase in the number of standards applicable to the area and the constraints with which new industrial products must be compliant.

Optimization protocols relate not only to the world of mechanical engineering but now extends to almost all areas. For example "cost optimization tools that aim both at reducing costs as far as possible and to maximizing product quality are now used a lot", underscores Hossein Shakourzadeh. Altair even proposes a software package designed to help companies optimize their investments in software and associate equipment. So, when shall we see the advent of optimization tools to optimize the use of optimization tools? That is the question!