Monday, January 12, 2009
Sunday, January 11, 2009
High pressure waterjet in construction -An unknown technology
In order to gain a better understanding of how much the industry knows about waterjet technology, a survey was mailed out to various companies. A total of 215 surveys were mailed along with the cover letter and a self-addressed envelope for return. The construction companies were chosen out of the list provided by Associated General Contractors (AGC) in a random manner.
A total of 95 surveys were returned.
Approximately 42 percent of the companies are familiar with the waterjet.
Of the 42 percent who were familiar with its use, only about 17 percent of them actually employ this technology in their company.
Of the 17% who use the abrasive waterjet,
100% of them do employ another cutting technique.
88% percent use the pneumatic hammer,
63% use the diamond blade power saw,
19% employ other techniques such as torches, hydroblasting and grinders.
Of the 17% who employ the abrasive waterjet in their business,
56% use the waterjet for concrete cutting,
38% use the waterjet for steel cutting and
63% use the waterjet for cleaning and paint removal.
Of the 83% who do not use the abrasive waterjet,
76% use the pneumatic hammer,
83% use the diamond blade power saw,
9% use the mechanical brushes and
9% use other techniques such as verneer trenches and torches.
Conclusion and Limitations
It appeared after studying the advantages and disadvantages of the waterjet, that this is a tool that the construction industry should find very useful. Unfortunately, this does not seem to be the case. Many of the regional companies do not seem to have any significant knowledge of the waterjet, thus remaining unwilling to employ this technology.
The responses that we have received have left us with the inability to comment on the cost effectiveness of the waterjet in the construction industry. The majority of companies that we contacted do not employ the waterjet in their companies, nor d o most of them have any knowledge of the abrasive waterjet. These companies seem to be conservative to new technology and unwilling to take risks. This may also be due to the fact that many companies are unwilling to invest in a new technology that is not widely used.
REFERENCES
[1] Behringer -Plosonka, Catherine A., "Waterjet Cutting - A Technology Afloat on a Sea of Potential", Manufacturing Engineering, Vol. 99, Nov. 1987, pp. 37-41.
[2] Haylock, Rob, "Waterjet Cutting", Conference: Automach Australia "85, July 2-5, 1985, Melbourne, Australia.
[3] Slattery, Thomas J., "Abrasive Waterjet Carves Out Metalworking Niche", Machine and Tool Blue Book, July 1991, pp. 31-34.
[4] Hitchox, Alan L., "Vote of Confidence for Abrasive Waterjet Cutting", Metal Progress, Vol. 130, July 1986, pp. 33-34.
[5] Flow International, 1995.
[6] Steinhauser, John, "Abrasive Waterjets: on the ‘Cutting Edge’ of Technology", Flow Systems, Inc.
[7] "Jetpac Intensifier Pump - Model 40DT", Flow Specs, FS-130, Sept. 1989.
[8] Ayers, Gary W., "Principles of Waterjet Cutting", Tappi Journal, Vol. 70, Sept 1993, pp. 91-94.
[9] Zaring, K., "Advanced Abrasive Waterjet Hardware and Cutting Performance", 5th American Waterjet Conference, Aug. 1989.
[10] Hashish, M., "Steel Cutting With Abrasive Waterjets", 6th International Symposium on Jet Cutting Technology, April 1982.
[11] Vijay, M.M., "A Critical Examination of the Use of Waterjets for Medical Applications", 5th American Waterjet Conference, Aug. 1989.
[12] Medeot, R., "History, Theory and Practice of Hydrodemolition", 5th American Waterjet Conference, Aug. 1989.
[13] Schmid, R.F., "High Pressure Hydro-Milling of Concrete Surfaces", 5th American Waterjet Conference, Aug. 1989.
[14] Peart, John W., "Lead-Pigmented Paints - Their Impact on Bridge Maintenance Strategies and Costs", Public Roads, Vol. 52 Sept. 1992, pp. 47-51.
[15] Katausakas, Ted, "DOT Coasts Rusting Bridges With Layers of Problems", R&D Magazine, May 1990, pp. 43-48.
[16] Baldry, Ian, "Surface Preparation", Civil Engineering (London, England), April 1987, pp. 47-48.
[17] Falcone, Linda M. Tonkay, Gregory L., "Economic Feasibility of a Tool to Remove Rivets From Railway Bridges", Proposal to The Canadian National Railway, April 1990.
A total of 95 surveys were returned.
Approximately 42 percent of the companies are familiar with the waterjet.
Of the 42 percent who were familiar with its use, only about 17 percent of them actually employ this technology in their company.
Of the 17% who use the abrasive waterjet,
100% of them do employ another cutting technique.
88% percent use the pneumatic hammer,
63% use the diamond blade power saw,
19% employ other techniques such as torches, hydroblasting and grinders.
Of the 17% who employ the abrasive waterjet in their business,
56% use the waterjet for concrete cutting,
38% use the waterjet for steel cutting and
63% use the waterjet for cleaning and paint removal.
Of the 83% who do not use the abrasive waterjet,
76% use the pneumatic hammer,
83% use the diamond blade power saw,
9% use the mechanical brushes and
9% use other techniques such as verneer trenches and torches.
Conclusion and Limitations
It appeared after studying the advantages and disadvantages of the waterjet, that this is a tool that the construction industry should find very useful. Unfortunately, this does not seem to be the case. Many of the regional companies do not seem to have any significant knowledge of the waterjet, thus remaining unwilling to employ this technology.
The responses that we have received have left us with the inability to comment on the cost effectiveness of the waterjet in the construction industry. The majority of companies that we contacted do not employ the waterjet in their companies, nor d o most of them have any knowledge of the abrasive waterjet. These companies seem to be conservative to new technology and unwilling to take risks. This may also be due to the fact that many companies are unwilling to invest in a new technology that is not widely used.
REFERENCES
[1] Behringer -Plosonka, Catherine A., "Waterjet Cutting - A Technology Afloat on a Sea of Potential", Manufacturing Engineering, Vol. 99, Nov. 1987, pp. 37-41.
[2] Haylock, Rob, "Waterjet Cutting", Conference: Automach Australia "85, July 2-5, 1985, Melbourne, Australia.
[3] Slattery, Thomas J., "Abrasive Waterjet Carves Out Metalworking Niche", Machine and Tool Blue Book, July 1991, pp. 31-34.
[4] Hitchox, Alan L., "Vote of Confidence for Abrasive Waterjet Cutting", Metal Progress, Vol. 130, July 1986, pp. 33-34.
[5] Flow International, 1995.
[6] Steinhauser, John, "Abrasive Waterjets: on the ‘Cutting Edge’ of Technology", Flow Systems, Inc.
[7] "Jetpac Intensifier Pump - Model 40DT", Flow Specs, FS-130, Sept. 1989.
[8] Ayers, Gary W., "Principles of Waterjet Cutting", Tappi Journal, Vol. 70, Sept 1993, pp. 91-94.
[9] Zaring, K., "Advanced Abrasive Waterjet Hardware and Cutting Performance", 5th American Waterjet Conference, Aug. 1989.
[10] Hashish, M., "Steel Cutting With Abrasive Waterjets", 6th International Symposium on Jet Cutting Technology, April 1982.
[11] Vijay, M.M., "A Critical Examination of the Use of Waterjets for Medical Applications", 5th American Waterjet Conference, Aug. 1989.
[12] Medeot, R., "History, Theory and Practice of Hydrodemolition", 5th American Waterjet Conference, Aug. 1989.
[13] Schmid, R.F., "High Pressure Hydro-Milling of Concrete Surfaces", 5th American Waterjet Conference, Aug. 1989.
[14] Peart, John W., "Lead-Pigmented Paints - Their Impact on Bridge Maintenance Strategies and Costs", Public Roads, Vol. 52 Sept. 1992, pp. 47-51.
[15] Katausakas, Ted, "DOT Coasts Rusting Bridges With Layers of Problems", R&D Magazine, May 1990, pp. 43-48.
[16] Baldry, Ian, "Surface Preparation", Civil Engineering (London, England), April 1987, pp. 47-48.
[17] Falcone, Linda M. Tonkay, Gregory L., "Economic Feasibility of a Tool to Remove Rivets From Railway Bridges", Proposal to The Canadian National Railway, April 1990.
Monday, January 5, 2009
Simulation of pure waterjet cutting
Searching lately trough the AWJC web i found this amazing research from the technical research center in Chania - Crete - Greece. A member of the research team Mrs. Phys. Maniadaki Kyriaki (MSc) has uploaded the following interesting animation.
Simulation Details:
Compared with traditional and most non-traditional machining technologies, AWJ cutting technology has a number of distinct advantages, such as no thermal distortion, high flexibility, high machining versatility and good surface quality, easy integration with mechanical manipulators, low machining force and minimal burrs. The utilization of the AWJ cutting/drilling and in particular its application into hard-to-cut materials is growing. Consequently, the waterjet and abrasive waterjet technology has been a subject of research for a number of years and the main stream of research has been directed towards the understanding of the complex material removal mechanisms and the optimization of the process parameters (fluid dynamics and technological) for various applications
In the current study, work was undertaken to accurately simulate the pure water jet flow of the process. The flow has been divided into three regions, inside the waterjet nozzle, the waterjet flow into the air and the waterjet impact on a non-moving target material as well as the impact on a moving target. What distinguishes this project from previous work is that the overall waterjet process is simulated including the nozzle waterflow simulation. At this stage of research the waterjet velocity profile that is created at the exit of the nozzle is computed and its form is known vs. time. The main objective is to investigate and analyze in detail the material behavior under waterjet impingement.
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