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  Project No. WP1 397 Development Report Performance Test of a Stuart A. Busse TESTING INC. 390 River Rd. - Box 1060 Mark Michie Project Assistant Ryan Schott, P.Eng Project Engineer TABLE OF CONTENTS2. EXECUTIVE SUMMARY 3. PROJECT DESCRIPTION 4. REVIEW OF COMMUNICATION WITH TRANSPORTATION AUTHORITIES AND EXPERTS 5. PROJECT PROCEDURES 5.1 General 5.2 Clearance Measurements 5.3 Truck and Axle Weights 5.4 Dayton Wheel Test 5.5 Budd Wheel-Cracked Rim Test 5.6 Budd Wheel-Simulated Broken Stud Bolts or Lost Nuts 5.7 Failed Wheel Bearing 6. RESULTS AND DISCUSSION 6.1 Clearance Measurements 6.2 Dayton Wheel Test 6.3 Budd Wheel-Cracked Rim 6.4 Budd Wheel-Simulated Broken Stud Bolts or Lost Nuts 6.5 Failed Wheel Bearing 6.6Other Observations 7. CONCLUSIONS AND RECOMMENDATIONS 1. INTRODUCTION Stuart A. Busse (client) has designed, built, and made patent application for a restraining device for wheels of transport trucks and trailers. The device is intended to prevent these wheels from traveling unrestricted when they become accidentally detached. Unrestrained, detached wheels can cause property damage, injury or death or get lodged under the trailer causing the trailer to flip. Testing is required to assess the ability of the device to restrain an accidentally detached wheel. The client contracted Western Canada Testing Inc. (WESTEST) to conduct this testing. 2. EXECUTIVE SUMMARY The wheel retention device tested by WESTEST performed well during the simulated wheel failure tests. Video footage of all the tests accompanies this report. The device retained the wheels for all of the simulated wheel failures including loss of the wheel nuts on a Dayton wheel, a broken Budd rim, loss of wheel nuts/broken stud bolts on a Budd rim, and a wheel bearing failure. The test conditions were in place for a limited amount of time, so performance of the device can not be predicted for extended periods. During the Dayton wheel test, the weld between the restraining device and the braces failed. This was corrected by bolting the braces to the front and rear members of the restraining device instead of welding them. The client may wish to develop a wheel failure indicator device to alert the operator of a failed wheel condition and prevent any further damage. WESTEST conducted this project to provide an independent, third party assessment of this wheel restraining device. WESTEST cannot guarantee that the test procedure will necessarily apply to all conditions which may occur in subsequent usage. In a similar manner, WESTEST is not in a position to guarantee that the wheel restraining device will live up to all expectations. 3. PROJECT DESCRIPTION The wheel retention device is shown in FIGURES 1 and 2. The device was constructed of 9.5 mm x 100 mm (% in x 4 in) spring steel. The outside bar had a second piece of 9.5 mm x 100 mm (% in x 4 in) spring steel welded to it which formed an indent toward the wheel hub. The front and rear members, also made of the same material, connected the outside bar to a plate which was bolted to the trailer frame. The outside bar was bolted to the front and rear members. Shims were used to obtain the desired clearance between the tires and to the outside bar. Diagonal brackets of mild steel were welded to the plate and the front and rear members. The wheel retention device was installed at the same height as the center of the wheel hub. Red and white reflective tape was applied to the bar for improved visibility. The wheel retention device was tested by inducing a variety of common wheel failures and assessing its subsequent performance. No applicable test standard was available so several transportation authorities and experts were contacted to determine what conditions the device should be tested under. A review of communications with these authorities and experts is found in the next section. WESTEST conducted this project to provide an independent, third party assessment of this wheel restraining device. As no applicable test standard was available, the lost program was developed with the input of the client and some industry officials. WESTEST cannot guarantee that the test procedure will necessarily apply to all conditions which may occur in subsequent usage. In a similar manner, WESTEST is not in a position to guarantee that the wheel restraining device will live up to all expectations. 
FIGURE 1. Wheel retention device (a) outside bar, (b) front member, (c) rear member, (d) diagonal bracket  FIGURE 2. Wheel retention device (a) outside bar, (b) front member, c) rear member, (d) diagonal bracket 4. REVIEW OF COMMUNICATION WITH TRANSPORTATION AUTHORITIES AND EXPERTS WESTEST was unable to find any applicable test standard for this device. WESTEST contacted a number of transportation authorities for input into a suitable test program. The following were contacted: • Peter Zongora - Regulation Enforcement, Transport Canada • Ovi Colavincenzo - Ontario Ministry of Transport • Ray Gompf - Yondar International • Allen Tucker - Canadian Transportation Equipment Association • Cam Woolley - Ontario Provincial Police • John Neufeld - Regulation Development, Transport Canada • Ross Hill - Haines Dana (Wheel Manufacturer) The following is a list of some of the comments and suggestions given by the transportation authorities and experts on the history of wheel failures, retention devices in general, and a suitable test program. History of Wheel Failures: • in 2 of 40 wheel failures to date this year, the wheel has actually departed from the vehicle • 1 of 40 failures caused by over torquing studs • 15% to 20% of failures are bearing failures • bearing failure common • most problems are with Budd style wheels • metal fatigue and corrosion cause a small percentage of failure • maintenance is the key to solving the problems General Comments on Wheel Retention Devices • relative lateral motion of chassis to wheels in lateral motion could cause interference with wheel retaining device depending on suspension design (i.e. lateral suspension stiffness) • some people were not keen on wheel retention devices • some thought the idea was good, but research was required on such a product to ensure proper functioning of the device • wheel may shake violently during failure and cause the cage to shake off • The driver may not be aware of the wheel coming off traveling long distances with the wheel in contact with the device. This situation has the potential for causing a fire. • Some were concerned that a loose front wheel may lock up under the second wheel and cause the trailer to flip, which may be a bigger accident. • Cage could come in contact with curbs and embankments which might make the vehicle overwidth; this maybe a problem depending on the interpretation of regulations. • a warning system may be a better way to go, or might be a good addition to the retention device. Suggestions for a Suitable Test Program: • video tape events during tests • might use explosive bolts to cause bolts to break • use a "J" turn to place higher stress on component that is to fail • use a secondary retention system such as a nylon web sling, cable or chains for safety during tests • start off slow and work speed up • testing should be done with loaded trailer at highway speed • try to get the failures to occur at highway speed • cut studs to make them fail • remove axle nut and hold wheel in place somehow until at highway speed • use an outrigger on the trailer to keep it from going down when wheel fails • concrete blocks would be better than water tanks for weight due to lower center of gravity With these comments in mind, the procedures outlined in the following section were developed. The primary emphasis was on simulating the most common modes of wheel failure. Safety concerns were also considered in the design of the test. 5. PROJECT PROCEDURES 5.1 General Testing of the wheel retention device involved simulation of a variety of wheel failures. These failures were simulated on the front wheels of a tandem axle convertible flat deck/grain trailer. The failures were: • wheel nuts removed from Dayton (spoke type) wheel • budd wheel with rim broken outside circle of wheel nuts • failed stud bolts on Budd wheel • failed wheel bearing Testing occurred at the WESTEST test track at Rivers, MB; as shown in FIGURE 3. The test track circuit included straight-aways with speeds up to 90 km/h (55 mph) and corner speeds as low as 50 km/h (30 mph). Wheel failures were obtained when the truck was traveling as fast as possible. Test conditions included cornering at various speeds and radii, lane changes, and bumps. A set of bumps was created by taping eight, 3.05 rn (10 ft) pieces of 25 mm x 50 mm (1 in x 2 in) rectangular steel tubing to the concrete surface. These bumps were driven over at speeds of 80 to 90 km/h (50 to 55 mph).  FIGURE 3. Test Track Used for Wheel Retention Device Testing The distance around the track was 4.8 km (3mi) when using the two main runways and the taxiways at either end. Three rounds of the test track, approximately 14.4 km (9mi), was used for most tests. Distance around the large triangle was approximately 3.8 km (2.4 mi). Each trial run was video taped by driving beside the truck at a safe distance and generally at an angle ahead of the wheel. Prior to the trials, measurements were taken to determine clearances between the wheel retention device and the wheel itself. Every effort was made to create conditions that would provide a realistic test of the ability of the wheel retention device to prevent loss of the wheel. 5.2 Clearance Measurements Measurements made to determine the clearance between the wheel and the retention device were: • clearance between the tire tread and the front and rear members of the device • clearance between the outside bar of the device and side wall at the front and rear of the tire • clearance between the wheel hub and the device • distance from the device to the ground These measurements were made for the front wheels of the trailer axles on each side prior to testing. 5.3 Truck and Axle Weights The trailer was loaded with two, 5450 1 (1200 gal) plastic tanks full of water, which were placed over the trailer axles and strapped in place. This gave a gross vehicle weight of 27,520 kg (60,700 lb) and a trailer axle set weight of 15,080 kg (33,240 lb). One test was performed with a Dayton wheel (spoke wheel) as in FIGURE 1. The right wheel on the front trailer axle was used for this test. The wheel nuts were all removed and the intent was to remove two wedges. However, when the first wedge was loosened, all of the wedges became loose. Four of the wedges were tightened up again and then the nuts were removed. Three rounds of the test track, approximately 14.4 km (9 mi), were traveled during the test. 5.5 Budd Wheel-Cracked Rim TestThe left front wheel of the trailer was used for the Budd wheel tests. A good Budd rim was replaced with a rim which had been cut almost completely between the two large holes on either side of the rim as shown in FIGURES 4 and 5. Prior to testing the retention device on the Budd wheel, the braces on the device were replaced by bolting new braces to the front and rear arms instead of welding them. The outer bar used in the Dayton wheel test was also moved to the Budd wheel to be tested, simply because the reflective tape on this bar had already been damaged. 
FIGURE 4. Simulated cracked rim. FIGURE 5. Simulated Cracked Rim.Approximately 14.4 km (9 mi.) was traveled during this test. 5.6 Budd Wheel-Simulated Broken Stud Bolts or Lost Nuts Test Simulation of broken stud bolts was done by removing all but two of the studs from the Budd wheel hub and retaining the dual wheels with only the thimbles on the two remaining studs. This is shown in FIGURE 6. The aim was that when the trailer got up to speed, the studs would break or the thimbles would fall off, releasing both wheels. The truck was driven around the test track three times, traveling approximately 14.4 km (9 mi) during the test.  FIGURE 6. Two Studs and Thimbles Holding Wheels On. 5.7 Failed Wheel Bearing Test The outer wheel bearing partially failed in the previous test, so the cage and rollers of the outer bearing were simply removed from the spindle to create a complete failed bearing condition. A 3 mm (Ya in) round plate, 200 mm (7 3/4 in.) in diameter, was placed over the hub and held in place by the wheel nut as shown in FIGURE 7. This was done with hopes that the plate would hold the wheel in place until the truck was up to highway speed, when it could wear out or bend out of the way, allowing the wheel assembly to move laterally. It became apparent after one lap around the test track, that the plate did not fail as expected, so it was taken off. After taking the plate off, the vehicle was driven one and one-half more rounds of the same path around the test track and 10 laps of a shorter path, clockwise around the large triangle. The total distance traveled for this test was approximately 50 km (30 mi).  FIGURE 7. Plate Holding Hub on Spindle.RESULTS AND DISCUSSION 6.1 Clearance Measurements The clearance measurements taken prior to testing are presented in TABLE 1. |