Find the instantaneous center of a bolt group under loading
Summary
In order to calculate the force of each bolt in a bolt group under loading, an instantaneous center needs to be found. Once the instantaneous center is found, the whole bolt group intends to have a pure rotation at the moment and the deformation of each bolt is proportional to the distance between the bolt and the instantaneous center. With the deformation is calculated, the force in each bolt could be calculated.
Learning Goals
The students will learn how to use advanced programming tools to perform complicated mechanics analysis. The instantaneous center is not known prior to the design. An iteration has to be performed. In the past, the process is completed by long and tedious manual calculations. It can now be done in MATLAB through a simple iteration loop. This activity involves some thinking on computational skills and needs some understanding of connection design in structural engineering.
Context for Use
The class is for senior undergraduate students and graduate students. The class size is at 15. And North Dakota State University is a public state institute. The demonstrated activity is a classroom activity, which took two class sessions. Students need to have basic MATLAB programming skills in order to complete the task. This task is an important part of connection design in advanced steel structural system. The activity introduced here can be easily adopted in typical classroom settings.
Description and Teaching Materials
Two documents are provided for this activity. One is the source code, while the other one is a homework for this activity.
- The matlab code for finding the instantaneous center of a bolt group (Matlab File 937bytes Sep2 21)
- Homework for finding the instantaneous center of a bolt group (Acrobat (PDF) 65kB Sep2 21)
Teaching Notes and Tips
Some review of basic MATLAB knowledge is helpful, such as definition of variables, programming syntax, etc.
Assessment
The students performed well for the programming homework. Most of the students could perform the coding and calculate the force in each bolt accurately.
References and Resources
The resources have been uploaded in the supporting materials port.