Meeting 4/8/15

Mark Odorizzi, Daniel Synoski, John Vargo                                                                                    

4/8/2015

Group 42 Section 940

Week 2, Meeting 4

Objectives

Present design proposal to Dr. Mitchell

Discuss location of the shuttle shelter with Dr. Mitchell

Seek guidance regarding the next step of the project

Procedure

The first order of business was to present the design proposal to Dr. Mitchell. In comparison to other design teams, Dr. Mitchell predicted, the design proposal was far more in depth and prepared. However, if he were to be grading harshly, he had some suggestions. The proposal had allocated the correct amount of time to structural analysis and the 3D model. It did not, however discuss the time it would take to learn about load calculations and 3D modeling software. Dr. Mitchell suggested that the group research these subjects soon. The specifics came later in the meeting.

The next order of business was regarding the site and design itself. Dr. Mitchell knew that the group had a site location in mind already, but suspected that the deliberation process was thin. For both the location and ultimate design decisions, Dr. Mitchell suggested that the group create a criteria matrix. An example is shown in Table 4-1.:

Table 4-1: Criteria Matrix Example

	Weight	Solution 1	Weighted 1	Solution 2	Weighted 2	Solution 3	Weighted 3
Criteria 1	1	2	2	5	5	3	3
Criteria 2	1.2	3	3.6	4	4.8	4	4.8
Criteria 3	2	1	2	2	4	5	10
Criteria 4	1	4	4	5	5	5	5
Criteria 5	1	2	2	4	4	1	1
Total Score			13.6		22.8		23.8

The matrix should be filled out using a 1-5 scale with 1 being poor and 5 being great. Each criterion should also be weighted based on importance. The solution with the highest score gives a projection of what the best solution is. There is room for error and double checking each criteria weight, but it gives a relatively accurate result.

Dr. Mitchell then started a brief overview on structural analysis. He told the group that a structure should have a load strength around two to three times the average load expected. To demonstrate the compressive strength of a material Dr. Mitchell used steel as an example.

Figure 4-1: Stress-Strain Diagram of Steel [1]

This curve shows how materials act like like a spring as the stress increases linearly with the strain. Steel, especially is extremely elastic and will return to its original shape until the strain reaches its proportional limit. At this point the material will distort and not revert to its original shape and strength. This is the point that engineers get materials compressive strength.

The second problem the group is going to face structurally, according to Dr. Mitchell, is buckling. This is when a beam starts to bend and create more non-linear strain. This theory, called beam theory, is complex so Dr. Mitchell suggests that the group should start researching it in the next week.

At the end of the meeting Mark Odorizzi checked out surveying supplies from Dr. Mitchell’s office for the next weekend meeting.

Obstacles

The group faced problems thinking about the engineering problems holistically. Thankfully, Dr. Mitchell saw that there were potential difficulties ahead and warned the group to start researching now. There are no other obstacles to report.