With the goal of safer buildings and saving lives, scientists and engineers, through the simulation of many recent earthquakes, need to test building materials and structural designs. Using either a one or two-axis high force linear positioning stage from H2W Technologies, they can simulate the effects of earthquakes as large as the largest recorded earthquake in history, the 9.5 magnitude quake on the open ended Richter scale, in May of 1960 in Chile.
To generate the high forces accelerations necessary to simulate different types of earthquakes, including a transform plate boundary quake (a destructive type of earthquake), H2W uses three-phase brushless motors with Hall Effects guided by linear ball bearings.
In addition, accurately simulating the destructive forces of an earthquake requires precise linear positioning. One-micron resolution linear encoders provide positional accuracies to ± 20 µm and repeatability better than ± 5µm.
The standard high speed, high acceleration two-axis linear positioning gantry (shown on the left) has a stroke of 8 inches [0.2 meters] (in both the X and Y axes. The force in the X axis is 400 lbs [1780 N] continuous (1200 lb [5340 N] peak) and the force in the Y axis is 200 lbs [890 N] continuous (600 lb [2670 N] peak), although longer strokes and higher forces are available.
To simulate the shaking from an earthquake you can send the signal directly from the motion controller to the amplifier, or from the data, available from the web, you can use LabView and a DAQ card (available from National Instruments) to produce an analog voltage signal from the data file to output to the amplifier.
H2W also manufactures a line of high force linear positioning stages that have single-axis operation (as shown on the right). This stage has a standard continuous force of 84 pounds [374 N], and a stroke of 8 inches [0.2 meters], although longer strokes and higher forces (up to 250 pounds [1113 N] continuous) are readily available. H2W will design a customized stage to meet a customer’s specific needs.
• Linear motors for reliable and quiet operation
• Extensive data acquisition and control capability
• Easy integration of your structures, sensors, and actuators
• Fully documented system models and parameters
• Supports scaling and playback of earthquake data
• Synchronize motion profiles with multiple tables and/or other data acquisition systems
• Integrated safety features and limits
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