The shaking table can reproduce any ground motion, from synthetic motions to real earthquake records.The hydraulic actuator is capable of producing a stroke of 75 mm.The seismic motion can be applied to all three directions x , y, and z.
In this section, hardware of the experimental shaking table has been presented.A 3 d model of the system is shown in fig.1.This figure points out the elements composing a single degreeoffreedom dof shaking table with operation range of 0 15 hz, driven by a servohydraulic actuator a moving platform for specimens housing 1200 mm 2000 mm the platform can be considered.
Fig 2 servo electric shake table 1.1.4 servo hydraulic shake table servo hydraulic shake table is a closer look control based actuation mechanism.Servo based direction control valve is the heart of the entire system.Servo valve basically governs the flow and pressure of the oil to the actuator.Accordingly the actuator moves forward and.
The sensitivity results reveal a a potential strong dynamic interaction between the oil column in the actuator and the payload, and b the very important effect of the servovalve time delay upon the total shaking table transfer function.
Shaking table excited inplane by secondary actuator inplane actuator xsupported by secondary framework on table xexperiences inertia loads from table xneeds simple set up e.G.Hydraulic hoses, accumulators, hydraulic control stations etc are cumbersome.
Iterative feedforward control of single actuator system.The typical control scheme of shaking table system is shown in fig.5.Total 6 reference signals are defined for six degrees of motion of the moving table.This reference signal.3.
High bandwidth shaking table control for better simulation of earthquake motion.Realtime modal decomposition used to decouple control axes.Actuatorstiffness related modal dynamics are cancelled within the control loop.Experimental results shown for a 43 tonne overconstrained 6 dof shaking table.
In order to achieve this good testanalysis correlation, it was crucial to include a time delay in the analytical model of the shaking table system innovative feature of the model to account for the time lag in the response of the servovalveactuator system.
A shaking table with one horizontal direction of motion only, driven by a single hydraulic actuator, and loaded by a single degree of freedom test structure, is shown in fig.2.1.
The shaking table is analyzed for their frequencies and movement amplitudes that are.This procedure was conducted with the shaking table working without any load the actuator only interacts with the mass of.
Shaking table testing 3 shaking table actuator harmonic wave random wave figure 1 shaking table test 3 vibration generator test in the case of actual buildings, a vibration generator is often used to apply harmonic external forces.A vibration generator is.
Shaking table experiment of a model slope subjected to a pair of repeated ground motions.Joseph wartman jonathan d.Bray raymond b.Seed drexel university university of california university of california philadelphia, pennsylvania, usa berkeley, california, usa berkeley, california, usa abstract.
In addition to shaking table testing, hybrid simulation hs is becoming a favorable alternative experimental method to shaking table test.This is particularly useful for the development of novel structural components and systems, where only a small portion of the structure needed to be experimentally tested.
Using the pneumatic shaking table, a liquefaction test on saturated sand was conducted.During liquefaction, both the stiffness and acceleration response of the ground greatly decreased.In comparison to the sharp increase in excess pore water pressure epwp when liquefaction started, the dissipation process lasted for a much longer time period.
Multiaxis shaking table mast multiaxis simulation mast tables are designed for testing of a variety of different specimens in six degrees of freedom.These include components and subassemblies exposed to vibratory loads during vehicle operation from seats, dashboards and interior equipment components to engine mounts, and cooling modules.
Tion.The presence of a test structure on the shaking table modies the expression for ss, hs, and bs, thus giving a modied expression for the shaking table transfer function s.2.1.Threestage servovalve transfer function, h 5 s the functioning of a threestage servovalve characterized by an inner feedback control loop is.
Development of a shaking table for educational purposes yar zar moe htet, moe hein aung and quentin etaix department of civil and environmental engineering, worcester polytechnic institute wpi, worcester, ma 016092280, usa advisor professor dr.Yeesock kim and kemal sarp arsava moeheinagwpi.Edu, yarzarmoehtetwpi.Edu table of contents pg.
Two highperformance, relocatable sixdegrees of freedom shake tables are located in a trench along the north wall of the main laboratory.The tables can be controlled either independently or as a single, synchronized table.Together, the tables can.
Table loaded with 68 kips single degree offreedom structure with a height of 219 inches.The shaking table has 5 degrees offreedom, one horizontal, one vertical and 3 rotational degrees of freedom.When loaded with heavy and tall structures, the shaking table undergoes pitching rocking motion even in the absence of a pitch command signal.
Shaking table experimental program.The acceleration and horizontal displacement of the shaking table was monitored with an accelerometer and a lvdt attached to the table platform.The displacements of the facing panel were monitored using four lvdts placed against the wall face.Two accelerometers were attached to the facing panel at mid.