A Good Case of the Shakes Shipment simulator reduces damage, costs

J. Edgar Myles has a reputation for putting products through the wringer.

In 1996, Mr. Myles, president of Control-Power Reliance LLC, an affiliate of major production tooling supplier DCT, built the CP-R 6 Axis Simulator.

Affectionately known as the "seismic shaker," the machine tests the performance of containers, racks and dunnage used in shipping automotive parts and assemblies worldwide. "We've had a 100% success rate so far," he boasts.

"The cost of a vehicle today includes between 3% and 7% attributable to cost of damage during shipping," Mr. Myles says. "The bottom line is, producers want to know if the racks they're shipping parts in will protect or damage the product."

By simulating the transport of cargo, whether aboard a freighter headed for Europe or a truck bouncing along Michigan roadways, engineers have the opportunity to discover and redesign flawed packaging, ultimately saving millions in production and damage costs, he says.

In one CP-R study, a Chrysler minivan roof panel rack, which vertically holds 24 panels, experienced failure when the clamps securing them to the rack opened and released the parts in under 10 seconds of testing. Chrysler had already invested money in producing the racks and was forced to redesign based on the test results, the study indicates.

"Our objective is not to break the parts we're testing, but to predict failure," says Mr. Myles. Thus, CP-R simulates shipment of virtually every car part from the roof to the floor mats. "About three out of 10 racks tested will need modification," he points out.

The need for a transportation simulator this large became apparent when Chrysler Corp., in preparation for its 1998 LH program, began searching for a single source to take on project management, design, fabrication and testing, says Mr. Myles. "The testing requirements they wanted were all for six axes," he says.

"At that time, vibration testing was only performed in one-, two- or three-axis."

After conducting research across the U.S. and Europe, Mr. Myles built the "seismic shaker" with hydraulic actuators, controls and software purchased from England. "With the exception of the U.S. military, we now have the largest six-axis seismic simulator in the industrial world," he claims.

The 6,000-hp machine looks harmless enough. But when the six hydraulic arms that hold the shaker table high above the plant floor are activated, the cargo resting atop the platform shakes, rattles and rolls just as it would when traveling by ship, rail, aircraft or truck. Unlike earlier machines that only tested the bouncing motion of the Z axis, the machine, which is capable of holding up to 15,000 lbs. (6,804-kg), simulates movement incurred from the X, Y and Z planes, plus pitch, roll and yaw.

At the shaker's base is a 12-ft. (3.66 m)-thick concrete structure weighing 2.4 million lbs. (1.1 million kg). The concrete acts as an anchor for the simulator and prevents the motion created by the actuators or arms from spreading. The pressurized building that houses the simulator is enclosed by walls made of 70 lb. (32-kg) high-density concrete blocks and a roof designed for acoustical absorption. Without the building's customized features, the noise and tremors discharged from the simulator could "quake" the surrounding area.

During testing the computer reads programmed signals from a chosen drive file created from field data and sets the three vertical and horizontal actuators into motion. The company also develops actual drive files by having a team follow or ride along with cargo and daily download data recorded by sensors attached to the shipment. "We have one trip planned to Mexico in late July and then one to Graz, Austria, later in the year," says Mr. Myles. The actual drive file is then stored into the computer for future use.

Every incident the cargo experiences is recorded by both a video camera and by the computer's database. After testing is completed, the information is gathered and shared with the customer. "We'll redesign the packaging with customer input or just make the customer aware so that they can take the information back to their packaging engineers for modification," says Mr. Myles.

The seismic shaker's latest feature is an environmental chamber that tests the extreme temperatures cargoes may encounter during actual shipping. The chamber can reach temperatures over a range of -30oF to 130oF (-34oC to 54oC). "The environmental chamber is helpful in testing plastic components that may fracture or melt in extreme temperatures," Mr. Myles says.

Although he boasts the company's accomplishments in designing, engineering and manufacturing production testing equipment and systems to help customers verify specific product performance, he admits it is always looking for ways to improve testing procedures and packaging design.

Computer modeling of racks and dunnage without parts is one area CP-R is delving into. The computer modeling would take place prior to testing of the actual product and rack. Such a system has the potential to save time and money by revealing flaws in rack design before actual testing. "Another thing we're working on is a rack that will absorb the shock of a crate being dropped heavily by a hi-lo," Mr. Myles says.

CP-R also hopes to expand its life-cycle testing capabilities into markets such as the food industry. Mr. Myles visualizes using the DCT system for the safe movement of hazardous and/or nuclear waste as well.