Double Lap Shear Analysis

[jonhoward]

In the double lap shear case of a bonded joint can someone tell me the analysis standard. Basically, I am wondering if the equation is:

sig= (P)/(lxw) or

sig= (P)/(lxwx2)

if anyone can provide some guidance it would be very helpful!

 

[RPstress]

Total area of glue being sheared is indeed 2*l*w, so

average_shear_stress = total_load /(2 * bond_length * bond_width)

Test standard ASTM D 3528 might help with the basics.

Note that the average shear is less than the peak shear in the glueline (unless the substrates are very thick, such as in Ray Krieger's KGR adhesive shear measurement machines).

Also note that a good adhesive will have quite a bit of plasticity before it fails. It depends a lot on what you're bonding with what.