Horizontal force on glued surfaces

AI Thread Summary
The discussion focuses on determining the maximum tensile strength of glue under a horizontal pull of 2000 kg, which translates to a force of 19,600 Newtons. To calculate pressure in MPa, the area of the glue patch must be known, as pressure is defined as force divided by area. The distinction between tensile and shear strength is emphasized, noting that pulling horizontally typically involves shear strength, while pulling away indicates tensile strength. It is clarified that the force conversion from kilograms to Newtons is consistent regardless of orientation, as it relies on gravitational acceleration. The setup's deformation under load may result in a combination of tension and shear forces acting on the glued surfaces.
Hubert96
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I am conducting tensile test on a bigger scale. When the material breaks i have the maximum kilograms that can be a applied to the material. I pull horizontal in a rubber patches glued to a rubber sheet and i want to find the maximum tensile strength in the glue. How do i convert my 2000 kg pull to MPa if the pull is done horizontal?
 
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Welcome to PF.
A weight of 2000 kg represents a force of F = 2000 * 9.8 = 19600 Newton.
Find the area of the glue patch, a, in m².
The pressure is then; F / a pascal.
1 MPa = 1 000 000. Pa

If you are pulling the patch away from the sheet it is tensile strength.
If you are pulling the patch along the sheet it is shear strength.
Take care that the flexibility of the sheet does not permit a tear to propagate, like peeling a label from a surface. In that case a lower force is needed because the area is reduced to a line.
 
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Thank you for the answer, very helpful. :)
 
one more thing. Since the pull directions is horizontal is it then correct to multiply the kg with 9,8. I assume that is the acceleration due to the gravity?
 
Force = mass * acceleration.
A mass on Earth generates a force of; F = m·g
The scales you measure the force of 2000 kg with, were calibrated to read mass on the Earth's surface. Your force of 2000 kg is multiplied by 9.8 to convert it to force in Newtons. That is independent of orientation.

I assume your rubber sheet is also horizontal and you are measuring shear. You have not clearly specified the orientation of your test piece, which is why I explained the difference between shear and tensile forces.
 
Hubert96 said:
I pull horizontal in a rubber patches glued to a rubber sheet and i want to find the maximum tensile strength in the glue. How do i convert my 2000 kg pull
Wow, you have a rubber sheet that is withstanding a 2000kg (2kN? 19.6kN?) pull? Can you post a picture of the setup?
 
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Since patch and sheet will tend to deform under that horizontal load, you may have a combination of tension and shear loads acting simultaneously on the assembly.
 
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