msjoey
Materials
- Feb 20, 2007
- 23
Hi everyone.
I am modeling (or trying to) a truck tire inflated at 300 kPa, carrying a load of 1,000 kg (per wheel), on a rigid plane. The request came from design engineers who want to understand the relationship between contact patch vs vehicle weight vs inflation pressure. I figured I should start with a working model that gives me a footprint of the tire as it is loaded on a rigid plane (smooth "road"). Once this is achieved, I can change the vehicle weight and inflation pressure as design engineers wish to see.
To understand the problem and how Abaqus can be used to get a solution, I recreated the Hankook model in Abaqus Example Problems 3.1.1 and 3.1.2 Tire analyses.
Unlike the Hankook model I don't have enough material data to accurately represent the tire (rubber sections, ply layers, etc) so I modeled a quarter tire, meshed as solid hexas, and gave them the rubber properties from the Hankook model (hyperelastic -- polynomial strain energy, viscoelastic -- prony).
My method:
[ul]
[li]I want to first displace the tire onto the ‘road’ (rigid) to stabilize the model, in Step 1. Maybe an interference of 1 mm will be enough to establish contact.[/li]
[li]In Step 2 I apply 300 kPa to the inner surface of the carcass[/li]
[li]In Step 3 I apply the weight of the vehicle (say 1,000 kg per wheel) to see the tire footprint. I use Concentrated Force applied to RP at the center of the tire, connected to the bead* elements via kinematic couplings.[/li]
[/ul]
*the bead is where the rim "holds" the rubber carcass (just to clarify)
I have one model in Explicit and one in Standard. The Explicit model (with mass scaling) ran but with stress values all over the place, so I killed it. The Standard model converged but the carcass hardly deforms throughout Steps 2 & 3. For sure it's nowhere near real life.
What am I missing or doing wrong in my simulation? If necessary I can share my inp file. The tire is an off the shelf item therefore IP is not an issue.
Thanks in advance!
I am modeling (or trying to) a truck tire inflated at 300 kPa, carrying a load of 1,000 kg (per wheel), on a rigid plane. The request came from design engineers who want to understand the relationship between contact patch vs vehicle weight vs inflation pressure. I figured I should start with a working model that gives me a footprint of the tire as it is loaded on a rigid plane (smooth "road"). Once this is achieved, I can change the vehicle weight and inflation pressure as design engineers wish to see.
To understand the problem and how Abaqus can be used to get a solution, I recreated the Hankook model in Abaqus Example Problems 3.1.1 and 3.1.2 Tire analyses.
Unlike the Hankook model I don't have enough material data to accurately represent the tire (rubber sections, ply layers, etc) so I modeled a quarter tire, meshed as solid hexas, and gave them the rubber properties from the Hankook model (hyperelastic -- polynomial strain energy, viscoelastic -- prony).
My method:
[ul]
[li]I want to first displace the tire onto the ‘road’ (rigid) to stabilize the model, in Step 1. Maybe an interference of 1 mm will be enough to establish contact.[/li]
[li]In Step 2 I apply 300 kPa to the inner surface of the carcass[/li]
[li]In Step 3 I apply the weight of the vehicle (say 1,000 kg per wheel) to see the tire footprint. I use Concentrated Force applied to RP at the center of the tire, connected to the bead* elements via kinematic couplings.[/li]
[/ul]
*the bead is where the rim "holds" the rubber carcass (just to clarify)
I have one model in Explicit and one in Standard. The Explicit model (with mass scaling) ran but with stress values all over the place, so I killed it. The Standard model converged but the carcass hardly deforms throughout Steps 2 & 3. For sure it's nowhere near real life.
What am I missing or doing wrong in my simulation? If necessary I can share my inp file. The tire is an off the shelf item therefore IP is not an issue.
Thanks in advance!