Recent content by Mechaman

Apologies, the lbs per inch is what put me off. I didn't convert the units properly. However, 300lb/in is = 52kN/m at a 0.3m change in height. I'm getting (0.3)k = mg k = 5,640N/0.3m k = 18.8kN/m

Homework Statement A mass of 115kg is to be suspended from a spring. When the mass increases to 575kg, the spring will move. Find the spring constant k. (This is not from a textbook, it is a project problem for a vehicle unloaded and then loaded on the same spring). y1 is the maximum height I...

Hi Randy, I took the 3 g's from an accelerometer measurement from a study just to avoid any serious dynamic equations. I'm sizing the spring for now but sizing it for an impact load (16.5kN). Am I right in saying the spring should absorb all of it and dissipate that energy through the damper...

The problem is a trailer with 2 wheels at the back and one at the front. I used statics to find the reaction force for each axle. The front comes in at 5.5kN. The G force then if hitting a bump I'm setting to 3 gs. 5.5kN * 3 = 16.5kN maximum load at the front axle. The spring and shock being...

I have a static reaction force of the wheel at 5.5kN. The shock load will be around 16.5kN. Even at 5.5kN and 200mm travel I'm getting: k = 5.5kN / 0.2 k = 2.75kN/m k = 2750N/m k = 2750000N/mm The largest spring I see is rated at 437N/mm here...

Ok thanks I think I understand that part. I was using the formula for finding w but I should be finding strain energy. If strain energy is measured in n/m how would I say it needs to absorb 16kN at that point? Would the moment of the spring at radius R to the mean of the wire be what takes the...

Hi All, I'm trying to design a spring for use in a shock absorber for a college project but my calculations aren't making any sense. I know this is a big ask, but if anyone knows about this stuff I'd appreciate a look. The maximum load is 16.5kN and when it's sitting it will be 5.5kN The...

I'm sizing a shock absorber at the moment for a project and I have accelerometer readings of a road going over bumps (3 gs). I have already applied gravity to the load to get my 5.5kN If the weight of the static load at that point is 5.5kN would it be safe to say the spring needs to be sized to...

Great I think I understand now. Thanks for the help.

Would the axle be considered the same as wheel A when looking at it in section view?

Hi all, I have a problem with a 3 wheel trailer and sizing the wheels. Using statics, how would I solve this 3D problem by breaking it down? The trailer is sitting on rectangular section and a plate on top carries an even load of 3500kg (roughly 35kN) If I take a cross section A-A and try and...

Homework Statement https://imgur.com/a/AGJaN It's a project so not a textbook question. The Attempt at a Solution Given in imgur picture. [/B] I'm looking to solve for C. The problem is actually a trailer with 3 axles but simplifying here as 3 fixed points where the wheels would be. The...

Thanks for the explanation. Does that mean that I can take the amount of energy the shock absorber dampens and the remainder is in the spring surrounding the shock absorber? Hence, if i had a second or third spring under the seat, my damper could be even smaller each time I add a spring? Also...

I should clarify that the seat is attached to a base by a sort of leaf suspension set up. The shock absorber (with its own spring as well) will be mounted to the seat, connecting the seat to the base. If I know the weight of the person and I know the G force subjected to them, should I not be...

Hi everyone. I'm trying to work out what size shock absorber to use. It's going under a seat so just the weight of a man really that it has to support. I've found a website showing the equations I need but I'm not sure about one of the steps. In step 2 it asks force output of the motor/drive...