Rehder, H. and Rehder, G., "Accelerated Durability Tests of Commercial Vehicles Powertrains Performed on Road by a Towing Trailer with an Electromagnetic Brake," SAE Technical Paper 2015-36-0306, 2015, doi:10.4271/2015-36-0306.
Durability tests of commercial vehicles are performed on road running uphill and downhill as well as on flat roads; these tests take very long time and have high costs. To lower test time and costs, it is proposed to accelerate the durability tests of commercial vehicles power trains by using a Towing Trailer with an electromagnetic (EM) brake, developed in Brazil, simulating uphill. This Trailer was already presented ,  for cooling test simulation at 20 km/h on commercial vehicles up to 250 HP.In the cabin (cab) of the vehicle under test, there are the braking level control and a laptop, which receives wireless and registers the operational parameters of the Towing Trailer. The GPS in the truck cabin (cab) supply information such as time, speed, latitude and longitude allowing the control of the route.Strain gauges glued on the traction rod measure the traction and compression forces between truck and Towing Trailer, capturing the effect of EM braking forces, acceleration and deceleration of the convoy, gear changes and the geographical road influence.Measurements were performed with powerful trucks (420 HP and 360 HP), higher than the foreseen Trailer EM brake capacity, to evaluate the limits of the testing system on flat ground, at 20 km/h (normally used for cooling tests) and on roads with varied slopes, at speeds up to 80 km/h.By the variation of the EM forces through the current, it is possible to evaluate the contribution of the EM braking forces for the durability tests.