This is part two of a series of blog posts concerning the MIL-STD 810 Vibration Section. This blog was written with reference to MIL-STD-810G w/Change 1 dated 15 April 2014. DES has the experience and expertise to help you determine what profiles are appropriate for your product and to run your MIL-STD-810 vibration test. For more information, please check out Part 1 – MIL-STD-810 Vibration Testing Overview blog and our Vibration Testing services page.
Category 4 of Method 514.7 Vibration testing details the transportation random vibration environmental conditions from cargo interaction with vehicle suspension and structures with road and surface discontinuities. “This environment may be divided into two phases, truck transportation over US highways, and mission/field transportation. Mission/field transportation is further broken down into two-wheeled trailer and wheeled vehicles categories.”
Truck Transportation over US Highways Vibration Testing
This vibration test method is used when products or equipment will be transported by large trucks tractor-trailers commonly seen on US highways. The truck transportation over US highways random vibration profile is designed to simulate 1609 km (1000 miles) on interstate highways. The random vibration profile along each axis can be seen in the plot below in Figure 1. The length of this profile is 60 minutes per axis for each 1000 miles of transportation. For example to simulate 2000 highway miles, the vibration test duration would be 2 hours per axis x 3 axes = 6 hours total.
Two-wheeled Trailer Vibration Testing
The two wheeled trailer (TWT) random vibration profile is a subcategory under the Two-wheeled trailer and wheeled vehicles category. This vibration test method is used when products or equipment will be transported by two-wheeled trailers across paved, secondary, and cross-country road surfaces. The random vibration profile simulates the cargo conditions of a two-wheeled trailer from the forward supply point to the using unit. The length of travel to be simulated is 51.5 km or 32 miles. The length of this vibration profile is 32 minutes per axis and can be seen in the plot below in Figure 2. The vibration test duration would have to be increased accordingly for longer lengths of travel.
A typical two-wheeled trailer is shown in Figure 3.
Composite Wheeled Vehicle Vibration Testing
The composite wheeled vehicle (CWV) random vibration profile is another subcategory under the Two-wheeled trailer and wheeled vehicles category. The vibration profile simulates the cargo conditions of transport by trucks or semitrailers across paved, secondary, and cross-country road surfaces. The random vibration profiles along each axis can be seen below in Figure 4. The length of travel to be simulated is 800 km (500 mi) from the port staging area to the forward supply point. The length of this vibration profile is 40 minutes per axis for each 500 miles of transport.
Composite Wheeled Vehicles are military vehicles. A typical Composite Wheeled Vehicle is shown in Figure 5.