yassou
Mechanical
- Mar 13, 2015
- 69
Hi everybody
When the Engine working, Connecting rod Transfer Load from Piston to the Crankshaft. So We can Calculate That load from P-theta Data.
Now if we want to calculate the Pressure of that Load on Crankshaft, We need the Projected/Active area Between Connecting rod and Crankshaft. And this is the place i stuck ?!
Any Ideas Will be Welcomed.
With Best Regards.
Yassou.
P.S. I look The Hertz's Theory. and as far as i know it's not suitable for this situation.
because:
1. Hertz based his work on the assumption that the contact area was small compared with the radius of the ball or cylinder
2. Simplifying Assumptions to Hertz's Theory:
Hertz's model of contact stress is based on the following simplifying assumptions :
the materials in contact are homogeneous and the yield stress is not exceeded,
contact stress is caused by the load which is normal to the contact tangent plane which effectively means that there are no tangential forces acting between the solids,
the contact area is very small compared with the dimensions of the contacting solids,
The contacting solids are at rest and in equilibrium,
The effect of surface roughness is negligible.
3. Goodman and Keer compare the work of Hertz with a solution which permits the contact area to be larger, such as the case when the negative radius of one surface is only very slightly larger (1.01 to 1) than the positive radius of the other.
Refs:
1-Engineering Tribology By Gwidon Stachowiak, Andrew W Batchelor
2-Young W., Roark's Formulas for Stress and Strain, 7th ed, 2001
When the Engine working, Connecting rod Transfer Load from Piston to the Crankshaft. So We can Calculate That load from P-theta Data.
Now if we want to calculate the Pressure of that Load on Crankshaft, We need the Projected/Active area Between Connecting rod and Crankshaft. And this is the place i stuck ?!
Any Ideas Will be Welcomed.
With Best Regards.
Yassou.
P.S. I look The Hertz's Theory. and as far as i know it's not suitable for this situation.
because:
1. Hertz based his work on the assumption that the contact area was small compared with the radius of the ball or cylinder
2. Simplifying Assumptions to Hertz's Theory:
Hertz's model of contact stress is based on the following simplifying assumptions :
the materials in contact are homogeneous and the yield stress is not exceeded,
contact stress is caused by the load which is normal to the contact tangent plane which effectively means that there are no tangential forces acting between the solids,
the contact area is very small compared with the dimensions of the contacting solids,
The contacting solids are at rest and in equilibrium,
The effect of surface roughness is negligible.
3. Goodman and Keer compare the work of Hertz with a solution which permits the contact area to be larger, such as the case when the negative radius of one surface is only very slightly larger (1.01 to 1) than the positive radius of the other.
Refs:
1-Engineering Tribology By Gwidon Stachowiak, Andrew W Batchelor
2-Young W., Roark's Formulas for Stress and Strain, 7th ed, 2001