Investigation of Flight Loads Prediction using Multi-Body Simulation 2013-01-2317

Flight load prediction is used to identify the maximum structural loads in an aircraft during flight manoeuvres and gusts. The motivation for this research activity was to assess the feasibility of using Commercial-off-the-shelf (COTS) software applications in the context of flight loads prediction during the early phases of design for commercial airline aircraft, which may drive significant time saving. The COTS that was used was the multi-body software LMS Virtual.Lab Motion.

To build a relatively accurate model within the given time, existing FE models and aerodynamic data for a given aircraft model were used. Initially, the model was trimmed to a steady-level 1-g state. Subsequently, several gust cases were simulated. The results showed that a steady state was achieved before and after the gust, demonstrating the ability of the model to recover. It was also observed that the trends of the pitch angle and pitch rate response were very similar to the results obtained from validated “in-house” tools. Most importantly, two of the three main quantities for flight loads, namely shear force and bending moment were captured quite well with a post processing of LMS Virtual.Lab Motion outputs. The results compare reasonable well with other validated data, although differences can be observed mainly due to different assumptions and simplifications in the model. The wing tip deflection was also assessed during this research activity. However, these results deviated from the validated data gathered. This could be due to the simplification of the aerodynamic forces applied or the aeroelastic response.