Axle Weight Distribution
Axle Weight Distribution
(OP)
Hi
I'd like to ask you for some inputs on this problem I'm having.
I've done some axle weight load distribution calculation before for some trucks with two axles. However this time I've been asked to perform it for a tanker trailer truck, which is a tractor unit (1 steer axle at front and two driving axles in tandem at the rear) and the semi trailer which has a triple axle in tandem at the rear.
I have all the weights and the location of all centres of gravity of the semi trailer unit and the supplier information of the tractor unit loads on both front and rear axles. However, differently from the past calculations I've made this one is an hyperstactic problem as I have three reaction forces. The method for solving for the hyperstactic situation is rather complicated due to geometry issues and my guess is that there is some rule of thumb or simplification to solve this.
Does anyone have experience with this?
Kind Regards
I'd like to ask you for some inputs on this problem I'm having.
I've done some axle weight load distribution calculation before for some trucks with two axles. However this time I've been asked to perform it for a tanker trailer truck, which is a tractor unit (1 steer axle at front and two driving axles in tandem at the rear) and the semi trailer which has a triple axle in tandem at the rear.
I have all the weights and the location of all centres of gravity of the semi trailer unit and the supplier information of the tractor unit loads on both front and rear axles. However, differently from the past calculations I've made this one is an hyperstactic problem as I have three reaction forces. The method for solving for the hyperstactic situation is rather complicated due to geometry issues and my guess is that there is some rule of thumb or simplification to solve this.
Does anyone have experience with this?
Kind Regards





RE: Axle Weight Distribution
Frequently the two axles will be connected with a lever that works like a "teeter-totter" and whose purpose is to equalize the loading between the two axles. (Common on leaf-spring and rubber-spring designs)
Frequently the two (or more) axles will use air-bag suspension with the pressure equalized between the two (or more) axles in some way.
RE: Axle Weight Distribution
Thank you for your reply! Just took a look on what you said. However I think I may have not expressed myself clearly. My problem is that the group (tractor unit + semi trailer) has 3 suspensions, two on the tractor unit (front and rear) and one on the semi trailer, Hence a Hyperstatic problem.
I'm inclined to neglect the effects on the front suspension of the tractor unit and consider only the suspension under the fifth wheel and the semi-trailer for calculations. What do you think?
RE: Axle Weight Distribution
You will most likely have to consider the effects of fluid sloshing on the load distribution.
Norm
RE: Axle Weight Distribution
RE: Axle Weight Distribution
Thank you for your inputs, I gues that separating the problem is the best way to go, as you proposed Norm.
I made a simple sketch on my understanding of what you said, can you give it a look to confirm?
truckandbus
Thanks for the tip! I took a look on google but found nothing, is this material available for free somewhere? If so, could you point me towards it?
Regards
RE: Axle Weight Distribution