“Computational Civil Engineering - "Intersections" International Journal

“Computational Civil Engineering 2005”, International Symposium 253⎡r1R =⎢⎢M⎢⎣0KOK0 ⎤M⎥⎥r m⎥⎦where r 1 …r m = the corresponding relative importance factors for actuators. If all ofthese factors are equal, then the matrix R becomes easier to generate:(9)R = rI(10)where r = unique relative importance factor; I = diagonal 1 matrix (identitymatrix).Using the models like those in Figure 5, the idea that the active/passive controls arevery effective (even if the energy request is large) was risen. Typical results asthose in Figures 6 and 7 are obtained in all cases. The response reduction is seen inall forms: accelerations, velocities, displacements, stresses, in time domain or infrequency domain.0.2Top Displacement, El-Centro NS10FRF of accelerationDisplacement (m)0.150.10.050-0.05-0.1-0.15Passive ControlActive ControlResponse (m/s2)8642Passive ControlActive Control-0.20 5 10 15 20 25 30Time (s)Fig.6 Time-history displacement response00 2 4 6 8 10Frequency (Hz)Fig.7 Acceleration frequency response3. ACTIVE HINGED STRUCTURE AND STRUCTURAL ROBOTICSLooking to living beings one should observe that the active joints are the keys ofdynamic equilibrium.In Figure 8 the concept of an active joint, Structural Active Hinge or SAH, isfurther developed as compared to proposal from [1]. This is only for 90 degreesconnection but it is somehow easy to imagine versions for other situations. At theleft of Figure 8, the action is done through a linear actuator. The right part ofFigure 8, the active rotational moment is the mean for control.The above concept of active hinge is based on what it can be seen at humans oranimal joints, for example at the knee. One should think that these types of jointsshould be autonomous automatic systems, which must work in order to fulfill the