This group project took place during the spring semester of 2016 as an extra credit assignment for EGN 3310: Engineering Analysis – Statics course. Starting in the first few weeks of class, our professor asked us to start thinking of interesting static structures that we would like to analyze in order to understand more about how the structure preforms. When we came up with our idea, we would pitch the idea to him and tell him how we would analyze the structure. Then, at the end of the semester, all of the students would present their findings at the IDEAS (Interdisciplinary Display For Engineering Analysis‐Statics) showcase in the UCF Engineering Building Atrium. The project had some initial specifications listed below.
- Groups of max 4 students.
- Students must prepare a physical model related to some of the suggested cases. This model must be verified by hand calculations.
- Students will prepare a poster containing all the information regarding their project.
- Students will prepare a paper (around 5 pages).
- Students will present their project to their peers, professors, and judges.
- Groups will work on developing the main idea for the project and this must be approved in person.
When my group started brainstorming, we knew we wanted to pick a structure that had significant applications to our everyday lives and that helped us gain a better understanding of what we were learning in the course. In our statics course, we spent a significant amount of time talking about support structures. We also knew that the showcase was going to take place in the UCF Engineering Building Atrium. Those three thoughts led us to choose the uniquely designed staircase that sits inside the atrium of the UCF engineering building as our structure to analyze. That way when we were presenting our project we could simply point to the real world structure that we modelled right from our booth!
In our proposal to our professor, we said that we wanted to complete an analysis on why support structures were used and what kind of value they brought to the design of the staircase. After approval from our professor, we got to work. We decided to create two different models of the staircase. One model would be an exact replica of the staircase and one model would be a replica of the staircase without support members. Both would be 1:38 scaled models of the staircase. We then created those models out of balsa wood and in SolidWorks.
We wanted to test how much weight the models could hold, then use that data to give an accurate representation of how much weight the actual staircase could hold with and without support members. To test the balsa wood model we used UCF’s Hydraulic compressor and to test the CAD model we used the simulation tools inside SolidWorks.
We used the SolidWorks simulation tools to predict the load that would cause buckling to occur in our structure and the location of the structure where that buckling would occur. In the model without supports, the buckling occurred at the very top of the structure with a 284 N load. The visual is below.
In the model with supports, the buckling occurred at one of the supports on the first floor of the structure. The model was able to withstand an 892N load. The top view of the model can be seen below.
Balsa Wood Hydraulic Testing:
The two balsa wood models we created were tested in UCF’s Hydraulic Compressor. The compressor slowly compressed our models while applying more and more force to the structures. Then, a sensor sensed when the structure started to buckle and stopped the compression before anything snapped or broke. The data that was collected from the compressor can be seen below.
Our unsupported model withstood a 235.75 N load and our supported model buckled at a 765N load.
Analyzing and Applying the Results:
The SolidWorks simulation calculated a 31.8% increase to the maximum bearable load when the supports members were applied. The hydraulic compressor calculated a 30.8% increase in the maximum load when the supports members were applied to the balsa wood model. That means there was only a 1% difference between our theoretical model and our real-life model!
With these fantastic results, we could then confidently use our data to calculate what kind of forces the UCF Engineering Building Staircase could hold with and without support members. We used A36 Steel as our assumed metal that the staircase was made out of. We then used hand calculations to calculate that the Engineering Building Staircase could withstand a 348840N load. We then used our results to show that without supports, the structure could only support a 107502 N load.
All of these findings go on to prove how important it is to add supports to staircases and really any structure that needs to hold significant loads. When designing stairs, supports will help increase the maximum weight capacity of the structure by around 30% and do this in a way that is very efficient and does not require a significant amount of material. This will help save money and increase the safety of the stairs!
Our project paper can be seen here: link