The ISTA load stability
workgroup has reached a key stage in its mission to study long duration acceleration events.
Led by Smithers expert Michael Kuebler
, the workgroup has been busy conducting research to understand field inputs that create load stability issues and discussing the data to determine how their findings may be transformed into test methods for predicting the effects of these inputs.
The workgroup has classified two categories of events that can affect load stability:
- Impact events. This refers to a sudden event that creates a dynamic response with high acceleration and lower duration, ranging from ~10 to ~150 or even ~500 milliseconds. A few examples of impact events include a forklift impacting into a stationary unit load, a forklift stopping with a unit load, or railcars coupling together.
- Constant acceleration events. Unlike impact events, constant acceleration events do not have a quick impulse or jerk. Constant accelerated events are quasi-static events that are much longer in duration, such as braking in a truck or traversing a curve. These events are lower in acceleration but do have an acceleration rise time that must be accounted for.
“These two types of events are fundamentally different and may create different effects on a load’s stability,” said Kuebler. “As a result, we don’t recommend creating just one test to simulate both of these events until more research can be done.”
The workgroup has created and submitted a draft procedure to the ISTA
standards council that predicts impact events in a laboratory environment. The draft procedure is based on testing methods that Smithers has been using successfully for over ten years. Read the first two updates about the workgroup’s progress:
The road to a draft procedure for constant acceleration event testing may be much longer. The workgroup found very little existing research related to constant acceleration events, and the equipment needed to simulate these events in a laboratory setting is not commercially available. The workgroup has determined a set of potential test values for simulating constant acceleration events, but those values need to be validated with field data:
- Rise time of 500 milliseconds
- Acceleration of 0.3 g
- Hold duration of 3 seconds
Smithers has created a benchtop concept test unit that can achieve these specifications, but the height of test samples may create challenges if the concept is scaled up to be used for actual unit loads.
“At this point, we’re looking to secure some funding—either from ISTA or from a private client—to conduct more in-depth research into how we can replicate and thus test for these events in a laboratory setting,” said Kuebler. “This could create a jumping-off point for the distribution testing community to gain a deeper understanding of these events and improve our processes for simulating them.”
Companies who want to learn more or are interested in partnering with Smithers to conduct this research are encouraged to get in touch.
“This research could make a significant difference in how we approach load stability and unlock cost avoidance opportunities through lightweighting
,” said Kuebler. “With the right testing procedure, tailored to measure the unique effects of constant acceleration events, we can help companies improve load stability and thus cut down on product loss, improve supply chain efficiencies, and increase safety.”
If you would like to learn more about the results of the workgroup’s first round of research or discuss the possibility partnering with Smithers for the next stage, contact Michael Kuebler at (517) 322-2400 or email@example.com