A3-HOWARD

Calculations for Method of Joints:

The negative values indicate compression, the positive values indicate tension.  

Diagram of force on each member:

Bridge Designer Analysis Diagram:

In order for the results of the hand analysis to correspond to the online Bridge Designer analysis, the ratios of the length of the members must be correct to ensure that the angles are correct.  Each member must be scaled to the size of the actual length.  The angles between the members in the actual bridge must match the angles in the online bridge designer.  Members in the actual bridge that are equal lengths must also be equal lengths in the online bridge designer.  If the ratio between the members stays the same, the angles will also stay the same.


Knex Bridge Analysis Diagram:

This type of analysis is helpful in analyzing the Knex bridges.  The force on each connection can be estimated and how much force is necessary before a connection is broken because we can determine how much force each connector and member can support.  Using the method of joints and the bridge designer, we can estimate how much load the bridge can hold before the connections are broken from too much tension or compression force.  This information can be used to improve the design of the Knex bridge in order to hold a greater load with less members.  An issue I encountered with Bridge Designer is that it does not allow any design, the number of nodes is related to the number of members.  We had to reconfigure slightly our design to allow the bridge designer to calculate the tension and compression.