An Innovative Approach to Shaker Testing
- Monday, 02 February 2009
By Marc Marroquin
Director of Marketing
LMS North America
When it comes to testing products for long-term durability, shock exposure survival, or accelerated life testing, the classic technique most engineers turn to is vibration testing with a shaker table. These controlled experimental tests have been successfully employed in the worlds of automotive, aerospace, consumer products, and military testing for more than 50 years. This classic test technique is accepted by all industries when durability, survivability, and life-testing data are required.
Despite a long and proven track record, vibration shaker testing has its drawbacks. Shaker tests can be expensive, require dedicated test facility/ equipment and trained personnel, and can take days (sometimes weeks) to complete. On top of that, it is not possible to test an object until either a physical prototype or early production unit becomes available. By that time, most design decisions have been made and it is difficult to redesign the product to resolve problems identified during shaker testing. These facts have been accepted as “the way shaker testing is done,” since there was no better way to perform these types of tests.
In recent years, engineers have been turning to new technologies like CAE (Computer Assisted Engineering) to help develop products faster and more intelligently. The benefits of integrating CAE into an engineering program are well documented and provide time, cost, and development advantages that enable companies to get better products on the market faster. By applying CAE technology to shaker testing, a new technology is born: Virtual Shaker.
The Virtual Shaker technology is quite simple: simulating a vibration shaker test in the digital domain. By using simulation to “virtually shake-test” a device, many of the inherent disadvantages of physical shaker testing are minimized or eliminated. There is no need to wait until a physical device is available, the time and expense associated with shaker testing is dramatically reduced, the “virtual” testing is completely nondestructive, and Virtual Shaker simulations can point out problems well before hard design decisions are made.
Along with the obvious benefits pointed out above, Virtual Shaker testing also introduces the ability to play “what if” scenarios with products. Since the actual product to be tested is purely digital, engineers can quickly and easily make changes to the product and see what happens after the change has been made. By combining Virtual Shaker with optimization tools, it is possible to run hundreds of design iterations (changing mass, shapes, materials, boundary conditions, etc.) in automatic cycles to find the best-case scenario.
Virtual Shaker testing is being used today by several aerospace manufacturers and space research facilities to virtually shake satellites. The benefit to these engineers is clear — saving money and reducing mission failure risk. But you don’t have to be a satellite designer to appreciate the benefits of Virtual Shaker testing. This technology can be applied to almost any industry where shaker testing is common, such as automotive, aerospace, consumer products, medical devices, and more.