The main principle of airbag ship launching is changing the force of sliding friction into rolling friction. The rolling resistance coefficients are important for calculation of ship launching with airbags.
The mechanism of the resistance force during airbag rolling, is fundamentally different from the mechanism of rolling friction which occurs during rolling of the solid deformable body. The rolling friction coefficient of airbags and ground depends on the ground situation and airbag bearing forces. As user of ship launching airbags, don’t need to know what is three components of the rolling friction of airabgs rolling on ground, the safe estimated figure is enough.
An example of the reference values of rolling resistance coefficient (μ) of the typical air bag with diameter of 1.5 m and the compression deformation rate of 45 % is listed in below Table.
The regularities of rolling friction coefficient change :
- Airbag inner pressure increasing, rolling friction coefficient decrease
- Airbag working heights increase, rolling friction coefficient decrease
- With same pressure, bigger diameter airbags have bigger rolling friction coefficient
- Airbag rolls on Solid ground has smaller rolling friction coefficient than soft ground
According to the rolling friction coefficient figures of 1.5 mdiameter airbags and regularities of rolling friction coefficient changein under different conditions, airbag user can give a safe estimation of rolling friction coefficient for practical projects.