Thomas G. Came, Randy L. Mayas and Vesta I. Bateman .... _ i_ _ :!_ Sandia NationalLaboratories _. .... Albuquerque, NewMexico87185, USA ' _ i_ _ / ABSTRACT important design consideration. This would include payloador satelliteloads duringrocket launches[3]. Force reconstruction is a procedure in which the externally applied force is inferred from measured An applicationthat will be discussed as part of this structuralresponse ratherthan directlymeasured. In paper is the impact into a rigid barrier of a weapon a recently developed technique, the response system with an energy-absorbing nose. The nose acceleration time-histories are multiplied by scalar had been designed to absorb the energy of impact weights and summed to produce the reconstructed and to mitigate the shock to the interiorcomponents. force. This reconstruction is called the Sum of To evaluate the crush capabilityof the nose, impact Weighted Accelerations Technique (SWAT). One tests were performed, and the measured forcestep in the application of this technique is the displacement curve was compared to the design calculationof the appropriatescalar weights. In this objective. Figure 1 shows the weapon mass-mockup paper a new methodof estimatingthe weights, using with the energy absorbing nose hung from its launch measured frequency response function data, is rail and fixture. The mass-mockup was designed to developed and contrasted with the traditional SWAT have the same mass, center-of-mass, and momentmethod of inverting the mode-shape matrix. The of-inertia as the real weapon. Both axial and diagonal techniqueuses frequency responsefunctiondata, but impact tests of the nose were plannedso the mockis not based on deconvolution, up needed to possess the correct rigid-bodyinertiaas well as mass. Figure2 showsthe plasticdeformation This work was supported by the U. S. Department of '_ _,. Energy under contract No. DE-AC04-94AL85000. _,t _ ]L. __ c_ .Olr. _P_[J'i ;_; '} :" "H]_; D0/CUt_.Ft'4T J:_i.JIYLI,_ITF._ DISCLAIMER This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer er, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.
A new technique for force reconstruction is developed. To estimate the externally applied force, this technique sums the weight-scaled acceleration signals, and is referred to as the Sum of Weighted Accelerations Technique (SWAT). To obtain the scalar weights the inverse of the mode shape matrix is used. Application of this technique is illustrated with both numerical calculations using a mass-spring model and experimental data from a structure impacting a rigid barrier.
Two force reconstruction techniques were used to evaluate the impact test of a scale model nuclear transportation cask dropped 30 ft. onto an unyielding target. The two techniques are: the sum of weighted acceleration technique (SWAT) and the deconvolution technique (DECON). A brief description and the calibration of the techniques as applied to the cask are presented. For the impact test, both techniques yielded very similar resultant forces and provided more accurate definition of the force-time history for the cask than is available from conventional data reduction methods. An applied moment, measurement previously unobtainable from conventional accelerometer data reduction techniques, was determined with SWAT. The angular velocity calculated with SWAT was verified with photometric measurements.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.