For the Detailed Design Phase, any related content to this node will be in the Detailed Design Documents.
Team Vision for Detailed Design PhasePhase Objectives:
In this phase the team would like to accomplish these tasks:
- Redefine Scope
- Re-Design of Normal Tile
- Re-Design of Mold
- Create Test Samples
- Allocate budget
- Systems Design for Top Tile
- Integration of Top Tile to Roof System
- Purchase All Materials for Samples including:Cement, Sand, Pumice and Plastic
- Incorporate Top tile into full process
- Further Simulation of Manufacturing Process
In this phase, the team has divided these goals into these themes and assignments:
- Matt - will be leading and handling material requirements, testing and will work closely with Dan of sample creation
- Derick - will be leading project planning tasks, budget and process integration
- Dan - will be in in charge in the sample creation, normal tile re-design, and mold re-designs
- Connor - will be in charge of researching & furthering the manufacturing process
Preliminary Detailed Design Re-Cap and Progress Report
Re-Cap of Preliminary Detailed Design
For those that were unable to attend the presentation for the the Preliminary Design Review on Monday November 13th, click HERE for a link to our EDGE page. Some of the major decisions and accomplishments from this phase and review were:
- Creation of a Design of Experiments to guide our Sample Creation
- Creation of the Sample Mold (Mold for creation of samples for testing)
- Updates to Tile/Roof Design
- Updates to Steps in Process Diagram, upgrades to Simulation
Since our last review, the team has been working on the tile design, further work on the sample mold and DOE, as well as working on progressing/incorporating the top tile into the design process. Below are a list of some updates to keep an eye out for before the Detailed Design Review:
- The Sample Mold is planned to be bonded with clay, glue and bondo
- Samples will be created the week of the 27th and let cure until finals week
- Exploring new prototyping ideas, including 3D printing
- The manufacture of Ricardo’s tile has been identified, looking to benchmark against that company/ contracted organizations.
- Amendments are being created to the tile design for better coverage
The actual team progress report will also be posted HERE.
Normal Tile DesignDuring the preliminary detailed design phase, a new profile for the tile was proposed that allowed for better dimensioning of the tiles. This design was further improved during the detailed design phase by designing the tiles to stack better. Originally this idea resulted in tiles that were too thin, but this was corrected by thickening certain portions of the profile and rounding off sharp corners in order to improve the overall strength of the tiles. The changes to the profile design can be seen in the figure below.
Final Tile DrawingsThe new profile was also designed with ease of construction in mind, by referencing the bottom surface of the tile for dimensions as much as possible and using round, easy-to-manage numbers for these dimensions. The final schematic for this design of the tile is shown in the figure below.
SimulationIn order to confirm that the new design for the tile would be capable of meeting engineer and customer requirements, a stress analysis was conducted using PTC Creo CAD software. Our research has shown that normal concrete typically has a maximum tensile stress of between 400 and 700 psi. The simulation showed that the maximum principal stress experienced by the tile is 391 psi. Testing of our concrete samples will allow us to determine if this is an acceptable metric, or if we will need to further change the design of the tile to allow for decreased loads.
- Better stacking
- Thicker and stronger
- Two nubs for roof
- Dimensions based on bottom surface
Tile MoldTo create our tiles, we plan to create vacuum-formed molds into which we will place the concrete and allow it to cure. In order to gain a better understanding of the potential size and shape of the mold, models were made in PTC Creo. Two different ideas for mold design were explored.
2 Piece MoldThe 2 piece mold consists of a top and bottom piece that are designed to fit into one another as shown in the figures below.
1 Piece MoldIn order to solve the problems presented by the two-piece mold, a new, stackable designed was proposed.
Rapid Prototyping3D Printing was used as means of rapid Prototyping. The team decided that these prototypes can be used to exemplify the interaction of the tiles, prior to their creation. Team Member Dan was able to print multiple iterations of the tile design, so that stakeholders can compare in a visual and tactile way.
Top Tile DesignThis section covers the addition of the Top Tile Design. The team, tasked with the creation of the entire roofing system, is responsible for creating a top tile to finish off the complete roof design. The following sub-sections explain the purpose, design and choices behind the team's final design for the top tile. As a note, in previous iterations, there was no inclusion of the top tile. This year's team found it a crucial part of the roofing system to complete.
Systems Design for Top TileIn order to decide what design we wanted for the top tile, a morphological chart was constructed and discussed.
Choices for Top Tile
This was the final choices for the Top Tile Design:
Top Tile in Creo
The design for the top tile was modeled in PTC Creo in order to see the way it would interact with the other tiles on the roof, and to get an idea of what it would look like.
ChangesThe Process is almost identical, however there is the incorporation of a second production line. This would use mostly the same equipment, however the shaping and molding steps would be unique to eat tile type.
For each roofing system, there is only a need of 8 top tiles, and therefore, in terms of load, only 1 top tile is needed per 28 other tiles. This would mean that there would be much less mold and line infrastructure. Lines can be run once a week to meet weekly demand, or on a daily basis.
Updated Process Map
Manufacturing Bill of MaterialsBelow is the bill of materials for the manufacturing process with each process step separated into its own category. This allowed the team to dive into detail about what would be needed at each process step specifically.
= Manufacturing plan for MSD II-Design the optimal flow & layout for the system materials people and information
-Find a building that will achieve needs of the manufacturing system (shape,size, electricity, water, easy access from transport)
-Acquire a business student onto the team or look into the business side of the project and set up a task list that would be completed to establish the tile manufacturing business
-Determine or estimate a demand and determine a takt time (add buffer)
-Estimate the cost of buying equipment for manufacturing needs
-Determine number of workers needed
-Create standard work for processes
-Determine ideal inventory for each material
Sample Creation and Test PlansDuring this phase, the team was able to create the samples discussed in the DOE plans from last semester.
PurposeThe purpose of these samples is to be able to test the properties outlined in the DOE. AS a recap, these are the factors and levels being tested.
ProcedurePrior to creating the samples, the team created a testing procedure for creating samples. This procedure was followed to create all 27 samples. This procedure can be found HERE, and the following notes discuss the basic procedure followed: Sample Creation
- Portion the correct amount of: Pumice, Sand, and Cement
- Mix the proportioned amounts together, adding water to the mixture
- Clean surface (acrylic) of mold and Coat the insides of each sample mold cell with mineral oil
- Fill 2 rows of the sample cells with the concrete mix, following the requirements of the DOE
- Portion the correct amount of plastic
- Add plastic shreds to the remaining third of the mixture and fill the remaining row of sample cells with mix
- Move Mold to the Shaker table
- Shake Mold on Shaker table for 1 minute OR until the pumice has visibly risen to the top and cement has sunk to the bottom
- Move Mold to an open space in lab to dry
- Let sit for 24 hours
- After 24 hours, remove Acrylic bottom and flip mold.
- Remove all samples by pushing evenly on all parts of the sample.
- Take the specified samples to be cured in the appropriate ways: In the Water tub in the lab ,Wrapped in plastic, or Air Drying in the lab
- Remove samples after specified amount of time from their curing environment and prep for testing.
Samples and Pictures
Lessons LearnedDuring the process, the team was able to make a "lessons learned" log, to improve each consecutive sample creation, or for future testing. Below is an example of those lessons:
TestingTo test the highest tensile stress in the specimens, we will be utilizing ASTM Standard C293 Standard Test Method for Flexural Strength of Concrete (Using Simple Beam With Center-Point Loading). This is the same testing standard P17485 used. The logic for going with a tensile test as opposed to a compression test is because of the nature of the tile assembly. With the way the tiles are assembled and supported on the roof, the tiles will be in tension on the bottom surface. This is the anticipated failure mode.
Predictions from Literature or ObservationsThis subsection contains any predictions created by the team, in terms of how the results from our future tests will show:
- Prediction 1:The Onion Bag will produce the strongest samples
- Prediction 2:Wet Curing will produce the strongest samples
- Prediction 3:Changing Pumice levels will have little impacts on strength, however, this will impact costs and weight of samples greatly.
Test Roof Plans
Some of the engineering requirements are mapped to features of the assembled roof. To test that our roof meets those requirements, we need to construct a test roof made of tiles and a test roof made of zinc sheets. Since the zinc sheets are what are currently being used, we want to show that our roof has more benefits than a zinc roof.
- Frame is made from 2"x4" wood connected by metal plates
- C-beams are used for the tile supports
Full Test Roof
- Consists of 6 regular tiles and 2 top tiles
- Access door will be added to access inside of roof
- The model file can be downloaded here
TestsBelow are the tests that are going to be performed on both the tile roof and zinc roof.
Recap of TestingTo satisfy all Engineering Requirements, we need to be able to test against those requirements. Below are the respective tests for each Engineering Requirement. It is worth noting that the "Bottle String Width" and "Bottle String Length" requirements are contingent about the specimen testing that will be conducted at the beginning of MSD II.
- Have you closed out your most important risks?
A lot of our risks are long-term risks that can be closed out after testing and creation of roof tiles. Risks that have to do with the manufacturing process have been partially completed such as quality, but until we have a concrete process, mix, and needed equipment they cannot be closed.
- Do you have remediation plans for remaining risks?
Yes every risk has an action to minimize the risks and team members are consciously making decisions around these risks.
- Have any of these risks manifested themselves as problems?
The only the risks that could be manifested as problems would be that there are not be a demand for the new tiles in Nicaragua, the testing of samples does not lead in a definitive direction, and quality of tiles is not maintained.
- How did your risk assessment change? What can you learn from this?
The risk assessment started off with solely the tile, the installation process, and the manufacturing process and then evolved into more about our teams risks (manufacturing/installation→use/testing). I learned to think about the entire project instead of the final product.
Risk Assessment for MSD IIThis risk assessment looks into the biggest possible problems that can occur during MSD II
CommunicationsThese individuals were contacted ....
While searching for more information about the manufacture of concrete pumice, we encountered a company called Hess Pumice that provides a lot of information about this topic and sells pumice in various standardized sizes. They also stated that they have given samples and helped various schools with the NCCC (National Concrete Canoe Competition). We contacted Joel Blackner and Mike Hess Jr. of Hess pumice with questions about our mix design and whether they would be able to provide us samples. They agreed to send us free samples if we pay for shipping and gave us helpful advice about pumice as a pozzolan.
Subsystem Completion Table UpdatesBelow are the Subsystems Completion tables for Business and Tile end of the project. Looking at these tables, the team can see where it is on each of the subsystems that need to be focused on and completed: Business
Plans for next phasePlanned Action Items in MSD I, we didn't finish:
- Testing: Sample creation is timely because of multiple set ups and time of semester
- Vacuum Forming: Because of the two molds being designed, creation was stalled until next semester
- Further work on manufacturing: Too many unknowns, simulation still basic
The team will focus on these deliverables in MSD II:
- Testing of Samples to allow for best mix to be discovered and used for final concept
- Finalize both tile type molds, and create or order those molds
- Create Tile systems roof to use for testing of conditions
- Create documentation for the Manufacturing process
- Create a Business Plan including all the metrics for the manufacturing
Below is a Gantt chart for our plan.
By Month Planning:
- Finish Concrete Testing
- Complete Mold material test
- Complete Construction Plan for Molds
- Purchase Mold Materials
- Finalization of Concrete Mix
- Construction of Molds
- Continue Work on Manufacturing Side
- March (Pre-Trip)
- Pour Tiles
- Create Plan for Construction in El Sauce
- March (Post-Trip)
- Build Test Rig
- Test Tiles
- Finish Simio
- Facilities Design
- Finish Manufacturing Design
- Purchasing Plans Finalized for Business
- Prep for Imagine
- Finish Paper
- Finish Proposal
Our Vision of the Imagine RIT exhibit:
- Completed Test Roof
- Poster with Information of Testing in El Sauce
- Completed Tests