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Failure prediction of thin beryllium sheets used in spacecraft structures (Document No: 19940006718)
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Mascorro, Edward Roschke, Paul N. Serna, Oscar R. Papados Sr., Photios |
| Copyright Year | 1991 |
| Description | The primary objective of this study is to develop a method for prediction of failure of thin beryllium sheets that undergo complex states of stress. Major components of the research include experimental evaluation of strength parameters for cross-rolled beryllium sheet, application of the Tsai-Wu failure criterion to plate bending problems, development of a high order failure criterion, application of the new criterion to a variety of structures, and incorporation of both failure criteria into a finite element code. A Tsai-Wu failure model for SR-200 sheet material is developed from available tensile data, experiments carried out by NASA on two circular plates, and compression and off-axis experiments performed in this study. The failure surface obtained from the resulting criterion forms an ellipsoid. By supplementing experimental data used in the the two-dimensional criterion and modifying previously suggested failure criteria, a multi-dimensional failure surface is proposed for thin beryllium structures. The new criterion for orthotropic material is represented by a failure surface in six-dimensional stress space. In order to determine coefficients of the governing equation, a number of uniaxial, biaxial, and triaxial experiments are required. Details of these experiments and a complementary ultrasonic investigation are described in detail. Finally, validity of the criterion and newly determined mechanical properties is established through experiments on structures composed of SR200 sheet material. These experiments include a plate-plug arrangement under a complex state of stress and a series of plates with an out-of-plane central point load. Both criteria have been incorporated into a general purpose finite element analysis code. Numerical simulation incrementally applied loads to a structural component that is being designed and checks each nodal point in the model for exceedance of a failure criterion. If stresses at all locations do not exceed the failure criterion, the load is increased and the process is repeated. Failure results for the plate-plug and clamped plate tests are accurate to within 2 percent. |
| File Size | 11102482 |
| Page Count | 261 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19940006718 |
| Archival Resource Key | ark:/13960/t6m091c75 |
| Language | English |
| Publisher Date | 1991-01-01 |
| Access Restriction | Open |
| Subject Keyword | Structural Mechanics Structural Failure Metal Sheets Mechanical Properties Computerized Simulation Spacecraft Construction Materials Ellipsoids Finite Element Method Bending Fatigue Circular Plates Failure Analysis Beryllium Spacecraft Structures Prediction Analysis Techniques Loads Forces Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Technical Report |
