Beginning of Mathematical Modeling: Shear stress and crushing

During this week we started the mathematical modeling that will guide the progress of our project. The calculations performed are related to determination of the crushing stress and the maximum shear stress.

Shear stress occurs commonly in rivets, because it is an element that connects several parts of machines and structures, where there are cases where the shear stress will be simple (only one section) or double (two sections), as is the case with the joint design by the team, which connects three plates, as shown in Figure 1, whose areas where the shear can occur are indicated in red.

                                                Image 1 - Area where shearing occurs in rivet.

Source: Adapted from SlideShare

The crushing stress was also calculated because the steel plate will compress the aluminum rivets, because the material used to manufacture the rivet has lower strength than the steel. Therefore, in the design of riveted joints, we must check that the crushing stress is below the permissible limit.

After the mechanical tests are carried out using the test specimens manufactured by the team, it will be possible to obtain the data related to the property of the material and that will be used to determine the next calculations, being able to obtain the information regarding the numbers of rivets that will be used , its dimensions and its safety factor.