Pneumatic tires are designed to meet five main goals: low rolling resistance, low vertical stiffness (to cushion the ride), high sliding friction in both wet and dry conditions, high longitudinal and lateral stiffness (to minimize sliding motions in the "contact patch" where the tread meets the road), and resistance to wear and damage such as cutting, puncturing, and abrasion.
However, in reality, the stiffness of the cushion system is nonlinear and the damping effect cannot be ignored in the drop-impact process.
"They looked like big Frankenstein boots," he said, "but in all cases people who wore these shoes said, 'Wow, this is a really great feel.' " Over the next few years, he tinkered with several more versions, trying to resolve issues in controlling a shoe's stiffness while providing good cushioning and durability.
It is also found that softer foams with low stiffness are more effective as shock absorbing cushion against ballistic impacts under certain condition.
Considering the importance of such evaluations to patient safety and quality of life, we studied the biomechanical performances of an ACB cushion in comparison to standard, flat foam cushions with different stiffness properties.
After gearshift and during the clutch re-engagement, the cushion disc allows to transmit a progressive torque through its axial stiffness.
The nonlinear axial elastic stiffness of the riveted clutch disc is described by the cushion curve which is an important technological constraint prescribed by car manufacturers.
A nonlinear quarter car model comprising of quadratic tyre stiffness and cubic stiffness in suspension spring, frame, and seat cushion with 4 degrees of freedom (DoF) driver model was presented for optimization and analysis.
This change did not modify the attachment of the cushion of the LP-ESP 2® prosthesis but made it possible to reduce its stiffness during compression by 30%% without changing its characteristics for flexion/extension, lateral incline, or rotation (Fig. 4a c).
