COMPUTATIONAL ASPECTS AND RECENT IMPROVEMENTS IN THE OPEN-SOURCE MULTIBODY ANALYSIS SOFTWARE "MBDYN"

This paper discusses some development directions recently followed with the aim of further improving the performances of the general-purpose multibody software MBDyn in terms of computational time. MBDyn is a free software that allows to simulate the dynamics of a broad class of mechanical and multidisciplinary problems, ranging from the real-time simula- tion of very small models, to the investigation of the dynamics of complex and large deformable aeroservoelastic systems. Very specific performance improvements may not be exploitable over- all the entire range of applicability of the code; as a consequence, different strategies have been investigated, with the common aim of being of the broadest possible usability. The directions that gave the most interesting results were: sparse matrix handling, assembly and linear solu- tion; incomplete and iterative nonlinear problem solution; parallelization of matrix assembly and factorization. The paper illustrates the rationale behind the investigation of these imple- mentation issues, the results obtained so far with reference to the typical problems MBDyn is used for, and the directions of further investigation.

[1]  Paolo Mantegazza,et al.  Assessing the local stability of periodic motions for large multibody non-linear systems using proper orthogonal decomposition , 2004 .

[2]  Paolo Mantegazza,et al.  REAL-TIME MULTIBODY ANALYSIS OF WIND-TUNNEL ROTORCRAFT MODELS FOR VIRTUAL EXPERIMENT PURPOSES , 2003 .

[3]  Paolo Mantegazza,et al.  ASSESSING THE LOCAL STABILITY OF PERIODIC MOTIONS FOR LARGE MULTIBODY NONLINEAR SYSTEMS USING POD , 2003 .

[4]  Pierangelo Masarati,et al.  A Multibody User-Space Hard Real-Time Environment for the Simulation of Space Robots , 2003 .

[5]  Paolo Mantegazza,et al.  TOWARD A COMPUTATIONAL FRAMEWORK FOR ROTORCRAFT MULTI-PHYSICS ANALYSIS: ADDING COMPUTATIONAL AERODYNAMICS TO MULTIBODY ROTOR MODELS , 2004 .

[6]  Giuseppe Quaranta,et al.  Further Results of Soft-Inplane Tiltrotor Aeromechanics Investigation Using Two Multibody Analyses , 2004 .

[7]  C. Kelley.  Iterative Methods for Linear and Nonlinear Equations , 1987 .

[8]  Yousef Saad,et al.  Iterative methods for sparse linear systems , 2003 .

[9]  Marco Morandini,et al.  Using dense storage to solve small sparse linear systems , 2007, TOMS.

[10]  Paolo Mantegazza,et al.  TRAJECTORY OPTIMIZATION AND REAL-TIME SIMULATION FOR ROBOTICS APPLICATIONS , 2005 .

[11]  Paolo Mantegazza,et al.  Multibody Analysis of Controlled Aeroelastic Systems on Parallel Computers , 2002 .

[12]  Marco Morandini,et al.  A REAL-TIME HARDWARE-IN-THE-LOOP SIMULATOR FOR ROBOTICS APPLICATIONS , 2005 .

[13]  Marco Morandini,et al.  Open-Source Multibody Analysis Software , 2003 .

[14]  Paolo Mantegazza,et al.  DYNAMIC CHARACTERIZATION AND STABILITY OF A LARGE SIZE MULTIBODY TILTROTOR MODEL BY POD ANALYSIS , 2003 .