User:Eml4500.f08.ateam.nobrega/hw 1

8/25/08
Dr. Vu-Quoc reviewed the class syllabus in detail. The topics that will be learned in the eml4500 include matrix algebra and its application to finite element solution, linear stability analysis of beam/truss structures, and construction of a FE code. He also intoduced the concept of collaborative learning; we will be working in teams throughout the semester to complete homework reports. Each team is responsible for summarizing each leacture and identifing confusing or ambiguous points discussed. All of the teams' input will be used by Dr. Vo-Quoc as feedback and address any underliying issues if necessary. Each student is reponsible for creating their own wikipedia account to complete their homework. I am confused about how to submit or post information on my wikipage. I am unfamiliar with the interface and controls.

8/27/08
Wikipedia is a free open-content encyclopedia. The articles are written by users and can be edited by anyone with a wikipedia account. For this reason, vandalism is a concern. However, if a students wokr is vandalized the previous version of the article is available in the history and can be restored quite easily. Also, an archived copy of the final collective assignment must be created and submitted to the professor and teachong assistants as to avoid problems with vandalism. Groups working on similar research can collaborate across the globe using the various wikipedia applications.

Trusses, Beams and Frames (Ch4)
Trusses are structural systems arranged to resist primarily axial forces. Beams are long slender members that are commonly subjected to normal loading with respect to their longitudinal axis; as a result, they must withstand shear and bending forces. Frames can be viewed as a hybrid between trusses and beams because they are meant to resist bending and axial forces. Consider a truss composed of two elastic (deformable) bars as shown in Figure 1. The bars are fixed (constrained to zero displacement) at the two ends shown and a known force P is applied at the joint of the two bars. By inspection one realizes that there are four reaction forces, one in the x direction and one in the y direction of each fixed end. However, only 3 equations can be formed with the given information. Thus, this problem is statically indeterminate.

Another method may be appropriate to solve this problem. First, inspect the system as a whole by drawing a global force body diagram (FBD). Then analyze each individual component by drawing bar element force body diagrams. These diagrams are featured below; the global FBD corresponds to Figure 2 and the FBDs of bar elements one and two are represented in Figures 3 and 4 respectively.