TESTING ON SYSTEMS OF ALL SIZES
The most realistic way to determine if a component will withstand an earthquake and remain functional is to put it through one. In accordance with the code, active or energized components are required to be certified exclusively through shake table testing or experience data. TRU Compliance is regularly engaged in shake table testing on systems of all sizes, whether small components weighing 20 lbs or large, complex systems in excess of 100,000 lbs.
The most common testing procedure used for IBC and OSHPD applications is the International Code Council Evaluation Services Acceptance Criteria 156 (ICC-ES AC156). This criteria specifies a specific input motion to which nonstructural components should be subjected.
Input motions are required to be 30 seconds in length with a stationary input motion over a broad range of frequencies. This input motion requirement is derived based on ASCE design provisions. Required response spectrum shape is derived based on building code provisions.
Shake table testing can be performed on a range of table types including uni-axial, bi-axial and tri-axial.
TYPES OF SHAKE TABLES
TRU Compliance maintains a network of partner and affiliate shake table testing labs throughout the US to serve our clients needs and schedules. There are a variety of type of shake tables appropriate for use in a seismic certification program. Many factors are involved in determining the most appropriate testing location, such as: size and weight of the component, facility location, timeline and complexity of the program.
Tri-axial tables provide the most realistic seismic simulation as they are capable of generating seismic motions in all three orthogonal directions simultaneously. By using a tri-axial table, the amount of time required at the test lab is minimized, as the number of seismic runs and setup is the lowest.
Unlike a tri-axial table, uni-axial facilities are capable of shake table testing in one direction at a time. While there are uni-axial facilities that can test larger components, TRU Compliance utilizes these types of facilities for smaller components only. These testing locations are most utilized for testing control panels and similar devices, due to their cost competitiveness on test articles of this size. When using a uni-axial table, the duration on site is typically longer as more setup time and seismic runs are required.
TRU facilities are located throughout the United States and abroad, and include small, private testing labs and large, government facilities capable of testing components well over 100,000 lbs.
CUSTOM TEST FIXTURES
Often times, the size or configuration of a test article requires the design and fabrication of testing fixtures to accommodate seismic testing. TRU Compliance has extensive experience in the design and fabrication of fixtures for use in shake table testing and has a wide variety of standard fixtures on site at our partner labs. Whether it is a vibration isolation frame, ceiling suspension system or wall mount panel, TRU has the expertise to provide cost effective, high performance assemblies.