Strength, Calculation and Testing of Bonded Joints

Strength, Calculation and Testing of Bonded Joints For thermal expansion it generally applies ... 

Secondly, the layered structure causes interlaminar shear stresses at each layer interface together with other in-plane shear stresses. Therefore, it should also be verified that the allowable in-plane shear stress of the adherend is not exceeded. This is not included, however, in the conditions above, as the interlaminar shear failure is typically preceded by a throughthickness tensile failure. The required value of the interlaminar shear strength is also seldom available, and there are no standardised test procedures to determine such a value. As a result, bonded joint induced interlaminar shear stresses are not calculated in the design procedures presented. 

Another tensile test, ASTM D2095-72, involves the testing of bar and rod butt joint specimens. ASTM 2094-69 describes the preparation of these specimens (see Figure 3). This test and the samples can be used with substrates comprised of metals, plastics, or reinforced plastics. Loads are applied through fixtures connected to the samples by dowel pins. The standard test rate is 2400 to 2800 lb per square inch of bond area. The maximum load at failure is used to calculate the tensile strength, the same as for the pi-tensile specimens. 

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