Load Test Your Design

How to design a bridge

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Once you have a complete, stable , you must run a simulated to ensure that all of the in your design are strong enough to carry the prescribed in Design Specification 5.

To load test your design:

  1. Click the .
  2. Sit back and watch. The West Point Bridge Designer 2010 will perform the load test, display the load test animation, and update the load test status display.
  3. Once the load test is complete, click the to return to the Drawing Board.

Notes and Tips

When you click the Load Test Mode button, the West Point Bridge Designer 2010 will automatically perform the following actions:

  1. Create and supports at the appropriate locations in your structural model.
  2. Calculate the weight of all members, and apply these to the structure as loads.
  3. Calculate the weight of the bridge , , and (see Design Specification 5 for more information), and apply the corresponding loads to the structure.
  4. Apply the to the structure at multiple positions, representing the movement of the truck across the bridge.
  5. Check the structural model for stability. If the structural model is unstable, the West Point Bridge Designer 2010 will attempt to fix the problem. If it is unsuccessful, it will stop the load test, inform you of the problem, provide some suggestions for fixing it, and return you to the Drawing Board.
  6. Perform a , considering the combined effects of the bridge self-weight and truck loading. For each truck position, calculate the of each joint and the for each member in the structural model.
  7. For each member, compare the calculated member forces for all truck positions, and determine the absolute maximum force and the absolute maximum force. These are the critical forces that determine whether or not a given member is .
  8. Calculate the tensile strength and compressive strength of each member.
  9. For each member, compare the absolute maximum tension force with the tensile strength, and compare the absolute maximum compression force with the compressive strength. If the force exceeds the strength in either case, the member is unsafe; if not, the member is safe.
  10. Prepare and display the load test animation.
  11. Update the load test status display.

To save time, you can run the load test without displaying the load test animation. Use the to switch off the animation.

If you don't want the West Point Bridge Designer 2010 to attempt to automatically fix an unstable structure, you can use the to switch off this feature.