Accession Number : ADA264882


Title :   On the Feasibility of a Transient Dynamic Design Analysis


Descriptive Note : Technical rept.


Corporate Author : MARYLAND UNIV COLLEGE PARK DEPT OF MECHANICAL ENGINEERING


Personal Author(s) : Cunniff, Patrick F ; Pohland, Robert D


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a264882.pdf


Report Date : May 1993


Pagination or Media Count : 43


Abstract : The Dynamic Design Analysis Method has used for the past 30 years as part of the Navy's efforts to shock-harden heavy shipboard equipment. This method which has been validated several times employs normal mode theory and design shock values. This report examines the degree of success that may be achieved by using simple equipment-vehicle models that produce time history responses which equivalent to the responses that would be achieved using spectral design values employed by the Dynamic Design Analysis Method. These transient models are constructed by attaching the equipment's modal oscillators to the vehicle which is composed of rigid masses and elastic springs. Two methods have been developed for constructing these transient models. Each method generates the parameters of the vehicles so as approximate the required damaging effects, such that the transient model is excited by an idealized impulse applied to the vehicle mass to which the equipment modal oscillators are attached. The first method called the Direct Modeling Method, is limited to equipment with at most three-degrees of freedom and the vehicle consists of a single lumped mass and spring. The Optimization Modeling Method, which is based on the simplex method for optimization, has been used successfully with a variety of vehicle models and equipment size.


Descriptors :   *MATHEMATICAL MODELS , *DAMAGE ASSESSMENT , *SHOCK(MECHANICS) , *MECHANICAL ENGINEERING , OSCILLATORS , TRANSIENTS , OPTIMIZATION , STRESS ANALYSIS , EXPERIMENTAL DESIGN , ACCELERATION , DYNAMIC RESPONSE , ELASTIC PROPERTIES , DEFLECTION , TEST EQUIPMENT , DEGREES OF FREEDOM , SHOCK RESISTANCE , VEHICLES , SPECTRUM ANALYSIS , DYNAMIC TESTS , SPRINGS , SHOCK SPECTRA


Subject Categories : Machinery and Tools
      Marine Engineering
      Test Facilities, Equipment and Methods
      Mechanics


Distribution Statement : APPROVED FOR PUBLIC RELEASE