SAMTECH to demonstrate Wind Turbine Structural Dynamics at EOW2009

Liege, Belgium: SAMTECH announces its participation in the European Offshore Wind energy Exhibition and Conference (EOW2009), which will be held from the 14th to the 16th of September in Stockholm, Sweden. This event will be an opportunity for SAMTECH to demonstrate advanced Structural Dynamic analysis of Wind Turbines using the new commercial release of its engineering software platform “SAMCEF for Wind Turbines (S4WT)”.

The industrial engineering process of large Wind Turbines is a complex organisation involving several teams of engineers, with complementary expertise. During the last 30 years, a lot of advanced engineering software has been developed by wind energy expert researchers, and method engineers of Wind Turbine manufacturers. These software tools are applicable to various disciplines and are usually used sequentially, often requiring iteration loops.

Step 1: The first category of mechanical engineering software is dedicated to the evaluation of dynamic loads in various conditions, working from inputs generated by Aerodynamics (CFD), Aero-elasticity, and Control Design teams. Load computations are usually performed with low fidelity Beam Finite Element models of the Wind Turbine, computing extremely fast in order to cover, in a practical time frame, a wide range of wind conditions, justified by the wind stochastic character.

Step 2: The dynamic internal loads extracted from the previous calculations are then translated into envelopes of equivalent static loads for the local Stress Analysis of Wind Turbine structural components. In this context, linear or non-linear structural analyses are performed using general purpose FEA software available on the market.

From the Finite Element Analysis results, a decision can then be taken to update the wind turbine design. During this iteration process, the design modifications of the structural parts are used to update the equivalent beam properties of the previous dynamic load computations. These computations are then repeated (returning to Step 1) until the designers are satisfied.

In the case of Wind Turbines with a mechanical power-train, dynamic loads are given in parallel with specifications to the gearbox manufacturer. The manufacturers will usually perform kinematical design of its mechanical gearing system using simple torsion models, or sometimes 3D rigid Multi-Body Simulation software. This design activity is usually undertaken separately; in particular without strong interaction with the flexible behavior of the blades under the effect of the wind.