Bricard Mechanism 2005-08-30 Dynamic simulation of the Bricard mechanism Laboratorio de Ingeniería Mecánica Manuel González Castro Manuel González Castro González Castro Manuel J. Lolo Universidad de la Coruña Laboratorio de Ingeniería Mecánica Escuela Politécnica Superior lolo@cdf.udc.es +34 981337400 Mendizabal s/n Ferrol 15403 España

The Bricard mechanism is a classic example of overconstrained system. It is composed by 5 rods of 1 m length with a uniformly distributed mass of 1 kg, and 6 revolute joints. The system is under gravity effects (9.81 N/kg acting in the negative y direction).

Grübler formula gives 0 degrees-of-freedom for this mechanism, but the particular orientation of the revolute pairs yields a system with 1 degree-of-freedom.

Bricard mechanism

The analysis to be performed is a dynamic simulation with a duration of 600 s. Initially, the system is at rest in the position shown in the figure.

The reference solution for this problem is the time-history of the position of point P3 (x, y and z coordinates). The maximun allowed errors are 1.0E-1 (low precission) and 1.0E-3 (high precission), measured with 3000 output steps and a threshold value of 1.0E-3.

The following information is provided:

  1. Time-history of the position of point P3, as text data file: A04_solution_data.txt
  2. Animation of the system, as AVI movie (first 10 s): A04_solution_movie.avi
  3. Time-history of the position of point P3, as plot (first 10 s):

    Time-history of the coordinates of point P3

 CPU-time spent by the software to solve the problem (in s).