Download or read book Finite Element Modeling of the RAH 66 Comanche Helicopter Tailcone Section Using Patran and Dytran written by Mark S. Gorak and published by . This book was released on 2001-06 with total page 109 pages. Available in PDF, EPUB and Kindle. Book excerpt: The United States Army contracted Boeing-Sikorsky to develop the RAH- 66 Comanche, a new, armed reconnaissance helicopter that features stealth technology designed to improve survivability when operating in hostile environments. Ballistic testing is required on any new technology, to include the Comanche, prior to fielding. Computer based simulations are being employed to reduce the requirements for expensive live fire testing. This thesis uses computer programs called PATRAN and DYTRAN from MSC Software Corporation to build the model and simulate the effects of an explosive round detonating in the Comanche tailcone section. This thesis describes in great detail the process of creating and modifying the model in PATRAN to most accurately depict the Comanche tailcone section and creating the input decks for DYTRAN to run the analysis. A test case involving an explosion with a high amount of explosive energy, or specific internal energy (SIE) was simulated. From this test, several results are shown to display the capabilities of DYTRAN. These results, when compared with live fire data, can be used to validate the computer-based simulation in order to reduce the requirements of expensive live fire testing.

Download or read book Analysis of Potential Structural Design Modifications for the Tail Section of the RAH 66 Comanche Helicopter written by Vincent M. Tobin and published by . This book was released on 1997-06-01 with total page 119 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Army RAH-66 Comanche Helicopter made its first flight in January of 1996. Its current structural configuration, however does not meet the Army's requirements for radar signature. Structural configurations of the tailcone that meet radar cross-section requirements tend to lack sufficient structural stiffness due to the presence of Kevlar in place of graphite on the outer mold line. This thesis investigates potential structural design modifications to the Comanche tailcone that would move the design closer to meeting both its structural and radar signature requirements. Geometry modifications with baseline (current configuration) materials increased torsional stiffness by nine percent. Structural geometry modifications using radar signature compliant materials reduced torsional stiffness by 10 percent. The geometry changes analyzed produce structural performance improvements insufficient to allow the use of radar-compliant materials without further geometry changes.

Download or read book Analysis of Potential Structural Design Modifications for the Tail Section of the RAH 66 Comanche Helicopter written by Vincent M. Tobin and published by . This book was released on 1997-06-01 with total page 117 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Army RAH-66 Camanche Helicopter made its first flight in January of 1996. Its current structural configuration, however, does not meet the Army's requirements for radar signature. Structural configurations of the tailcone that meet radar cross-section requirements tend to lack sufficient structural stiffness due to the presence of Kevlar in place of graphite on the outer mold line. This thesis investigates potential structural design modifications to the Comanche tailcone that would move the design closer to meeting both its structural and radar signature requirements. Structural geometry modifications with baseline (current configuration) materials increased torsional stiffness by nine percent. Geometry modifications using radar signature-compliant materials reduced torsional stiffness by 10 percent. The geometry changes analyzed produce structural performance improvements insufficient to allow the use of radar- compliant materials without further geometry changes.

Download or read book Computerized Ballistic Modeling of the Comanche Tailfan Shroud written by Allen H. Stephan and published by . This book was released on 2000 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The U.S. Army has contracted Boeing-Sikorsky to develop the RAH-66 Comanche, a new, armed reconnaissance helicopter that features stealth technology designed to improve survivability when operating in hostile environments. Ballistic testing is required on the Comanche prior to fielding. Computer based simulations are being employed in order to reduce requirements for expensive live-fire testing. This thesis uses a computer program called Dytran from MacNeal-Schwendler to simulate the effects of an explosive round detonating in the Comanche tailfan shroud. Six test cases involving explosions with varying amounts of explosive energy, or specific internal energy, are evaluated. From these tests, a curve showing the percentage of structural failure versus the specific internal energy is plotted. Assuming that 20% structural failure of the model equates to a catastrophic failure, this analysis shows that the analyzed section of the Comanche tailfan shroud can withstand an explosion with a specific 10 2 2 internal energy of 2.58 ̂ 10 in Isec . Any potential threat rounds with specific internal energies greater than 2.58 ̂ 1010 in2/sec2 will ose serious threats to the Comanche.