We are making a number of important changes to the Structures application. Please read below for updates.
For middle school students, the floor is no longer modifiable. The purpose of this change is to ensure that middle school students are focused on truss design - which is what the research materials are all about. To ensure that students are focused on the truss, it is also important to establish a default floor that is much stronger than the trusses. Otherwise the overall bridge capacity would be limited by the floor. We are still working on this, but any changes we make in the default floor should not have a material effect on your student's existing designs.
It is possible that these changes may conflict with some specifications. The default floor, for example, has laminated balsa wood for floor beams. This is allowed in all default WhiteBox specifications, but if you have a custom specification that does not allow laminated floor beams, then your students will be out of spec and will not be able to correct the issue. If this happens, you will need to change the specification to allow laminated floor beams. Note also that specifications for roadbed width and overall bridge width are ignored in the middle school application. This is because the default floor design includes a fixed width (which affects floor beam length).
The default bridge and fixed floor is displayed below:
The high school application has not changed as of yet, but you will see some changes in floor analysis in the coming week(s). All inputs are unchanged, but we do expect some changes in reported floor capacity. This should not be disruptive, however, because we believe that the current floor capacity is a bit understated. In other words, if anything, bridge designs will be a bit stronger than reported and any design that is in spec now will still be in spec after these changes have been made.