TECOSIM gets in tune

The grand piano is regarded as the king of instruments. Know-how for its design is based on several centuries of experience. This tradition in craftsmanship is important for master piano and harpsichord builder Jan Enzenauer, but it is not enough on its own for the perfectionist. Enzenauer has thus also adopted modern engineering methods to design an innovative grand piano. Such methods particularly apply to the cast frame, into which the piano strings are attached. Enzenauer Flügel-Manufaktur has commissioned TECOSIM to optimise the design of this element based on complex digital simulation. Use of knowledge from other sectors such as the automotive industry represents a visionary move which sets an exemplary precedent for the musical instrument industry.

The aim of the project is to increase consonance in the sounds from the flake-graphite cast iron frame by optimising its design. When the strings are struck, the cast frame transmits the vibrations from the strings to the wooden sounding board, which then produces the actual sound of the piano. The lower the energy losses due to dissonant vibrations in the frame are during transmission, the better the instrument will sound. However, the structural strength of the cast frame must not be impaired as the frame ultimately also needs to withstand the considerable force of the strings.

In order to calculate the complex acoustic processes taking place in the component, TECOSIM engineers have produced a digital model based on computer-aided design data (CAD). During this process, each individual string has been tuned in such a way that it vibrates at exactly the same frequencies as it would do in the actual instrument itself. „We have done the same on a computer as a piano tuner does on a real piano,“ says TECOSIM Project Manager Torsten Kroschwald. A very large, very precise model has thus emerged, which TECOSIM engineers will use to measure the exact behaviour of the new cast frame by means of computer simulation in spring 2013. The frame's transmission response to the sound board will determine the sound of the future instrument.

In addition to TECOSIM simulation specialists, Jan and Michael Enzenauer's company also chose the IfG – the Düsseldorf-based Institute of Casting Technology – as a partner for this research project, which is financed by the Federal Ministry of Economics and Technology based on a decision of the German Bundestag. Mark Gevers, Branch Manager at TECOSIM in Cologne, first exchanged preliminary ideas with Jan Enzenauer two years ago. The simulation of the sound characteristics produced by a complex musical instrument presented a new challenge for the calculation engineers. Before starting work on the computer, there was thus an initial stage when they carefully studied piano building techniques and the way that a grand piano works.

The pioneering project will not only be influential for the musical instrument industry, as Michael Enzenauer of Enzenauer Flügel-Manufaktur explains: „Our expertise is also of interest to the automotive industry, because the development of new car models also involves channelling vibrations and intensifying or absorbing them in a clearly defined partial range.“ The two sectors could thus learn from one another in different areas of design.