MSC 1984 World Users' Conference Proceedings

The conference proceedings for the 1984 World Users' Conference are now available on-line in Adobe Acrobat PDF format. (The Adobe Acrobat Reader software is available for free download from Adobe's web site at www.adobe.com). When printed, these PDF files will produce a better quality image than the one shown on your computer screen.

MSC TODAY (Acrobat 57 K) #0184, 1 pg.
J.F. Gloudeman -- MSC

Chart of the organization structure

MSC PRESENTS THE ENGINEERING APPLICATIONS DEPARTMENT (Acrobat 356K) #0284, 6 pgs.
D.N. Herting -- MSC

A PowerPoint presentation.

THE ADVANCED PROJECTS DEPARTMENT (Acrobat 70K) #0384, 1pg.
D.M. McLean -- MSC

ABSTRACT: The goal of Advanced Projects is to provide engineers with a complete integrated workstation environment.

STATUS OF MSC PRODUCTS, 1984 (Acrobat 1.72MB) #0484, 28 pgs.
M.A. Gockel -- MSC

A PowerPoint presentation.

GEAR ANALYSIS USING THE MSC/NASTRAN CYCLIC SYMMETRY APPROACH WITH ENHANCED GRAPHICS (Acrobat 1.19MB) #0584,13 pgs.
G.R. Parker -- Hughes Helicopters, Inc., Culver City, CA

ABSTRACT: The application of the cyclic symmetry approach in MSC/NASTRAN is applied to the modal analysis of a large finite element model of a helicopter transmission gear. Solution sequence 48, cyclic modes, is used with "axi" type symmetry. To enhance the post interactive graphics display, a modification was made to the graphics program to display assembled segment output deflections for any desired section, up to and including the full model. To verify the approach, a circular plate model was analyzed prior to application to the large gear model. Results for both analyses are presented. This technique was applied during the analysis of the Hughes AH-64A Apache Helicopter. The results show the obvious advantages offered by this method.

PRESS-FIT ANALYSIS OF AXLE ASSEMBLY USING MSC/NASTRAN NONLINEAR CAPABILITY (Acrobat 1.24MB) #0684, 17 pgs.
Hari Agrawal and P.R. Reumalswami -- Ford Motor Company

ABSTRACT: Experiences with NASTRAN material nonlinear capabilities applied to a practical finite element model are presented herein. A press-fit automotive assembly is analysed using MSC/NASTRAN MPC equations simulating the interference and the effects of material nonlinearities. Gap elements are introduced in order to study the effects of transverse forces which tend to loosen the joint. Also, some parameters of NASTRAN "NLPARM" card are studied in order to attain convergence.

CONNECTING SOLID FINITE ELEMENT MODELS THAT HAVE DIFFERENT MESHES ON THE MATING SURFACES (Acrobat 1.08MB) #0784, 18 pgs.
John L. Bretl -- Structural Dynamics Research Corporation

ABSTRACT: This paper describes a method to connect two solid models along surfaces that have non-coincident meshes, i.e., the grid points on the two surfaces do not line up. The essence of the method is that the displacement of each grid point on one of the surfaces is made dependent on the three or four surrounding grid points from the other surface. The MSC-NASTRAN interpolation constraint element, RBE3, is used. Element shape functions are used to determine the needed weight factors. The method allows two modelers to independently build complex solid models that eventually must be connected, without the constraint that the meshes on the connecting surfaces must match up. Also, the method is an easy way to transition from a coarse to a fine mesh, something that is normally quite difficult to do in a solid model.

FINITE ELEMENT THERMAL ANALYSIS OF DARLINTON TRANSISTOR STACK (Acrobat 1.21MB) #0884, 24 pgs.
Mark P. Zebrowski -- Ford Motor Company

ABSTRACT: The results of a three-dimensional, steady state finite element thermal analysis of a transistor stack consisting of a power darlington transistor, solder, a beryllium oxide heat spreader and an aluminum base plate are presented. The temperature rise of the transistor, which contains the heat generation source, predicted by the model is within 4% of the temperature rise measured in the laboratory. The model can be used as a basis for evaluating the thermal effects of alternate constructions of heat sinks and of variations in solder wetting.

STATIC GEOMETRIC AND MATERIAL NONLINEAR ANALYSIS OF AN S-FRAME USING MSC/NASTRAN (Acrobat 3.17MB) #0984, 59 pgs.

ABSTRACT: This series of analyses was conducted to assess the capability of MSC/NASTRAN. Version 61B, to perform a static non-linear analysis of an automotive component undergoing large displacements and having non-linear material properties. The problem chosen was that of a symmetric S-frame under static crush loading. Results from physical tests and also from competitive analysis programs can be found in the references, and were used to judge the validity of the MSC/NASTRAN results. Because of the estimated cost to perform the testing, the physical test data was taken from SAE Paper 770614.
The project described in this report was to see how close MSC/NASTRAN would predict real world crush performance for the initial deformations, up to and slightly beyond the development of a maximum simulated barrier force. Once MSC/NASTRAN has shown to be capable of predicting the maximum barrier force, at the correct crush distance, and with accurate energy absorption measures, the intent is to continue, and document in a subsequent report, the performance prediction to at least 6 inches of crush. Pending successful completion of the non-linear static analysis, dynamic effects could be included using a newly-released capability of MSC/NASTRAN.

TELESCOPING ROBOT ARMS (Acrobat 833K) #1084, 13 pgs.
Thomas G. Butler -- Butler Analyses

ABSTRACT: This tells a tale about a challenge in modeling a highly articulated structure with colinear beam elements in preparation for an eigenvalue analysis. Many is the time that you have heard a client say, "I just want a simple beam model to give me some preliminary answer." Sometimes the words simple and beam are contradictory. The completed model looks simple when plotted, but the ingredients that went into the beam to represent the equivalent structure were highly complicated. This paper gives a good example of a non-simple simple-beam model.

THE USE OF MSC/NASTRAN AND EMPIRICAL DATA TO VERIFY A DESIGN (Acrobat 2.80MB) #1184, 36 pgs.
William F. Ray -- PPG Industries

ABSTRACT: Because of the radical behavior of some materials under certain loading conditions, it is sometimes impractical (or even impossible) to verify a finite element solution by empirical means. This is especially true if the material being analyzed is a uniformly loaded, flat shell with extreme elastic-mechanical properties. This paper describes an approach used by PPG Industries to determine and understand the deflection, stress, and in-plane loads developed in this flat elastic shell by incorporating the data from MSC/NASTRAN's Geometric Non-Linear Solution, known as SOL 64, with an actual pressurization test.

COMPUTER AIDED ENGINEERING AND FINITE ELEMENT APPLICATIONS TO WEAPON SYSTEMS (Acrobat 1.18MB) #1284, 18 pgs.
Grant Parker and J.M. Lee -- Hughes Helicopters, Inc.

ABSTRACT: Finite Element methods and animated computer graphics were applied in the analyses of Hughes Helicopter 25mm and 30mm gun systems. In a joint project Hughes Helicopters, Inc. and SDRC, Inc. explored the application of CAE to the design of a weapon station for an Armored Fighting Vehicle (AFV). System dynamic analysis using component modal data for the 25mm gun and armored fighting vehicle was performed with aids of MSC NASTRAN and SDRC software with animated color graphic packages. During the course of the analysis a communication link was set up for transmitting converted NASTRAN output data between a CDC mainframe and VAX mini computer. The analysis procedure was documented on video tape. In a second analysis, the transient repose of the 30mm gun was performed by employing some of the non-linear load features in MSC NASTRAN. A fortran program was written to combine and convert NASTRAN linear and non-linear load outputs into plot format from which force time histories could be created. Parametric studies for optimizing the gun energy absorption system can be accomplished without involving extensive training.

APPLICATION OF SYMMETRY CONDITIONS IN RADIATION EXCHANGE BETWEEN SURFACES (Acrobat 855K) #1384, 15 pgs.
Mahesh Morjaria -- Xerox Corporation

ABSTRACT: For the analysis of radiation exchange between surfaces, it is not possible to take symmetry of a model into account in the present version of MSC/NASTRAN. A method which can substantially reduce both the computational and modelling effort by allowing symmetry conditions to be utilized in the analysis is presented. This method is based on the fact that the matrix of influence coefficients, required for the analysis, has a recognizable pattern in the case of symmetric models. This pattern can be exploited to reduce the computational effort. While derivation of the procedure is fairly involved, the final result can be easily implemented in MSC/NASTRAN through DMAP facility. The method is illustrated through a simple example. This approach can be universally applied to a number of other finite element applications.

FINITE ELEMENT ANALYSIS AND THE MODELING OF TIRES (Acrobat 1.15MB) #1484, 27 pgs.
D.V. Wallerstein and G.A. Dilley -- MSC

ABSTRACT: An area of continuing interest within the tire industry is the modeling and analysis of tires subject to general loading conditions. This paper will focus on the use of MSC/NASTRAN to model a typical radial tire. In addition to discussing this particular tire model and the results obtained from the analysis, some brief remarks will be given on the general topic of tire modeling and analysis.

STATIC AEROELASTIC ADDITION TO MSC/NASTRAN (Acrobat 1.54MB) #1584, 30 pgs.
W.P. Rodden, C.T. Wilson, D.N. Herting, E.D. Bellinger, and R.H. MacNeal -- MSC

ABSTRACT: The static aeroelastic problems of an elastic flight vehicle have traditionally been formulated in terms of flexibility influence coefficients or vibration modes. A new stiffness formulation has been developed and added to MSC/NASTRAN to solve the basic trim load problem and estimate the aeroelastic stability derivatives at subsonic speeds. The user options for symmetric and antisymmetric motions are illustrated in example problems.

EVALUATNG OPTICAL SYSTEM PERFORMANCE WITH MSC/NASTRAN (Acrobat 1.03MB) #1684, 13 pgs.
A. Hatheway -- Alson E. Hatheway, Inc.

ABSTRACT: It is possible to accurately evaluate the performance of optical components and systems using MSC/NASTRAN. Typical optical parameters are: Focus, tip and decenter errors, Surface figure changes, Image quality, Wave front quality, Boresight stability, Line of sight control. This paper discussed modeling techniques for evaluating two of these parameters, 1) Boresight stability and 2) Surface figure changes. The paper will be highlighted with examples drawn from recent practice which show the numerical and visual evaluation of these parameters.

CORRELATION OF A NASTRAN ANALYSIS WITH TEST MEASUREMENTS FOR HEAO-2 OPTICS (Acrobat 1.44MB) #1784, 25 pgs.
Pravin K. Mehta -- Perkin-Elmer Corporation

ABSTRACT: Since achieving and maintaining the specified geometrical accuracy of an optical form are important in the successful performance of an optical system, the analysis employed for the prediction of small elastic deformations of the system and/or its components must be sufficiently accurate and reliable. In this paper, the sagittal depth deviations of the paraboloids and hyperboloids of the HEAO-2 optics are computed by NASTRAN-based finite element analysis and compared with interferometrically measured test data. The correlation between the analysis and the experiment was found to be consistently excellent. The ensuing confidence in the analysis led to analytical compensation of sagittal depth deviation in each optical element during manufacturing, practically eliminating this geometrical error from the optical form.

LINEAR HEAT ANALYSIS BY MSC/NASTRAN AND ADINA-T (Acrobat 1.20MB) #1884, 26 pgs.
C.H.S. Chen -- The B.F. Goodrich Company

ABSTRACT: In this paper, a comparison is made between two thermal finite element codes: MSC/NASTRAN and ADINA-T. The capabilities of the two codes are compared in terms of the element library, material models, types of analysis available and solution algorithm. The performances of the two codes are examined by solving a linear transient thermal problem involving conduction and convection heat transfer. It is found that the temperature solutions of MSC/NASTRAN and ADINA-T agree extremely well if both use isoparametric elements. Use of the constant gradient elements of MSC/NASTRAN results in different, and perhaps less accurate, solution than that of isoparametric element. The performance of MSC/NASTRAN is further assessed by solving another linear transient thermal problem involving conduction and convection heat transfer and the results are compared with an analytical solution. The temperature solution of MSC/NASTRAN agree very well with the analytical solution at interior nodes but no so well at surface nodes where heat flux takes place.

AN EXCITING NEW TOOL FOR DISTRIBUTING COMPUTER AIDED ENGINEERING (Acrobat 713K) #1984, 9 pgs.
Kash Kasturi and Hal Boyd, P.E. -- United Information Services, Inc.

ABSTRACT: In recent years finite element analysis has begun to shift to 32-bit super-minicomputers. Increased productivity and cost performance are two of the major reasons for this shift. This paper will propose a plan for gaining even greater efficiency, productivity and cost savings by distributing data processing between a supermini and a supercomputer. V-LINK, a hardware and software communications system from UIS is a tool that satisfies the requirements for distributed processing by providing easy batch access from a Digital Equipment Corporation VAX computer to a CRAY-1S. Technical specifications of V-LINK are described in this paper.

APOLLO MSC/NASTRAN: A USER'S EXPERIENCE (Acrobat 1.0MB) #2084, 18 pgs.
Vern Overbye -- A.O. Smith Engineering Services

ABSTRACT: MSC/NASTRAN availability on the Apollo microcomputer was discussed at 1983 MSC/NASTRAN User's Conference. A.O. SMITH Data Systems Company acquired an Apollo computer in early 1983. This paper describes some of our experiences with MSC/NASTRAN. Particular emphasis is placed on structural analysis CPU time and elapsed time with comparisons made to a large main-frame computer. A variety of solution sequences have been used and experiences in each are discussed.

APOLLO/NASTRAN WORK STATION (Acrobat 1.84MB) #2184, 17 pgs.
G. N. Morrison -- Hughes Aircraft Company

A PowerPoint presentation.

DESIGN IMPROVEMENTS USING DESIGN SENSITIVITY ANALYSIS CAPABILITY OF MSC/NASTRAN (Acrobat 2.45MB) #2284, 52 pgs.
R. Narayanaswami -- CSAP Corporation

ABSTRACT: The capability to obtain design improvements in an automated fashion is useful, and often necessary, to design engineers. Engineers have, during the past thirty years, developed methodologies for automated design that vary in complexity from the simple stress-ratio algorithms of 'Fully Stressed Design' to the more complex algorithms based on mathematical programming techniques. Such methods are collectively known by various names as "minimum weight design", "structural optimization", "structural synthesis", etc. The evaluation of the sensitivity matrices (gradient of the constraints with respect to the design variables) is an important step in these methods. MSC/NASTRAN has introduced the design sensitivity analysis capability in Version 63 to evaluate the sensitivity matrices. This paper discusses the development of two software products CSAR/SIZING and CSAR/OPTIM that provide the MSC/NASTRAN users with the capability to obtain design improvements in an automated fashion.

SHIP VIBRATION ANALYSIS USING MODAL SYNTHESIS TECHNIQUE (Acrobat 1.56MB) #2384, 21 pgs.
Osamu Murakawa, Yoshio Iwahashi, Tsuneo Sakato -- Sumitomo Heavy Industries, LTD.

ABSTRACT: MSC/NASTRAN's modal synthesis technique was applied to the study of the complex vibratory phenomena of the afterbody of the ship. Calculated results were compared with those obtained by exciter test on the actual ship structure. Advantages and disadvantages of the modal synthesis technique, comparing to the ordinary direct method, were discussed in terms of computer resources, quality of the analysis model, and understanding of the complicated vibratory phenomena.

THERMAL ANALYSIS OF A PUMPED LIMITER- THE EXPERIENCE OF THE USE OF THE MSC/NASTRAN SOLUTION 89 (Acrobat 1.51MB) #2484, 23 pgs.
Solomon Dinkevich and Ahmed Shaaban -- EBASCO Services, Inc.

ABSTRACT: To increase the efficiency of the surface pumping panels installed in the TFTR Vaccum Vessel, it was proposed to add a perpendicular scraper blade as a reflector. The blade would extend in the space above the surface pumping panels towards the plasma. The Neutralizer plate, being close to the plasma will be subjected by particle collection to a very high heat flux of impulsive and repetitive nature. To define a probable configuration of the blade, the thermal and structural analysis was conducted using the MSC/NASTRAN computer code. Several important peculiarities of Solution 89 were found during the test. This paper discusses those complexities and how they were overcome. It also contains the solution to the above problem.

STRUCTURAL OPTIMIZATION WITH MSC/NASTRAN APPLIED TO GEAR HOUSING (Acrobat 2.08MB) #2584, 30 pgs.
Garret Vanderplaats -- Engineering Design Optimization
Mladen K. Chargin -- NASA-Ames Research Center

ABSTRACT: The purpose of this paper is to present a structural design optimization capability that is made possible by the sensitivity analysis option recently implemented in MSC/NASTRAN. In the past, a number of examples of relatively small scale were reported in literature using research oriented programs, but detailed descriptions of solutions of structural design optimization problems of practical scale and complexity are scarce. In this paper, application of a structural optimization capability to a practical structural design problem is described. The example structure is a large steel bearing housing as shown in Fig. 1. This example was selected because it had most of the attributes required to demonstrate important features of the design optimization system such as: large size, displacement as well as stress constraints, load combinations, multiple boundary conditions, and reasonable number of design variables.

RANDOM VIBRATION AND ACOUSTIC ANALYSIS USING ARI RANDOM, A NASTRAN POST PROCESSOR (Acrobat 2.77MB) #2684, 42 pgs.
R.D. Galletly, R.J. Wagner, G.J. Wang, J.W. Zins -- Jet Propulsion Laboratory, California Institute of Technology

ABSTRACT: This presentation describes the theory and application of ARI RANDOM. The results of three analytical studies are reviewed. These are: Wide Field Planetary Camera random vibration and acoustic analysis, Galileo Spacecraft acoustic analysis, and All Source Analysis System shelter transportation vibration analysis.

CREEP ANALYSIS CAPABILITY IN MSC/NASTRAN (Acrobat 1.61MB) #2784, 31 pgs.
Sang Hoon Lee, P.E. -- MSC

ABSTRACT: The creep analysis capability was introduced in MSC/NASTRAN Version 63. State-of-the-art theory and algorithms are employed to process the creep behavior coupled with the elastoplastic deformation at elevated temperatures. This formulation is based on the Maxwell-Kelvin rheological model. Various choices of empirical creep laws are available and small variations in temperature are allowed.

ACCURACY OF VIBRATION ANALYSIS FOR THIN CYLINDRICAL SHELL BY MSC/NASTRAN
(Acrobat 1.91MB) #2884, 28 pgs.
Naoaki Tokuda, Shinsuke Mitikami, and Yoshiuki Sakata -- Ishikawajima_Harima Heavy Industries Co., LTD.

ABSTRACT: The "good modelling" for the dynamic analysis by the finite element method are of importance for getting reliable results with minimum computational cost. Accuracy of QUAD4 and QUAD8 isoparametric shell elements in MSC/NASTRAN, when applied to the free vibration analysis of thin cylindrical shells having freely supported ends, has been investigated by numerical computations. The calculated eigen frequencies, the mode shapes and the corresponding stresses were compared with the theoretical solutions given by Arnold and Warburton. As far as the present analysis results are concerned, the excellent performance of QUAD4 has been revealed for a wide range of vibration forms, especially in calculating the membrane behavior dominant modes, which are of practical importance owing to their high excitability under pressure loading.