Overview Engineering calculations and simulation situation and trends
History Grow up from aircraft industry. Need for licht structures Need for strenght calculations Development of computer technology
History Hrennikoff [1941] - model of 1D trusses Courant [1943] Ritz methods application Levy [1947, 1953] - Flexibility & strenght Argyris and Kelsey [1954] Statics and dynamics prob. matrix based formulation Turner, Clough, Martin and Topp [1956] - 2D elements (Hrennikov evolution) Clough [1960] - Termin Finite Elements
History John Argyris Stuttgardi Ülikooli õhu- ja ruumisõidukite staatika ja dünaamika emeriitprofessor. TTÜ audoktor 1993. aastast, tunnustamaks tema väljapaistvaid teeneid lõplike elementide meetodi uurimisel ning Saksamaa ja Eesti teaduskoostöö arendamisel.
Development and implementation of CAD/CAM/CAE systems is one of the most important result in 20th century in technical sciences and technology. National Academy of Engineering American Society of Mechanical Engineering i
FEM - field of usage time 1990 1980 Process simulation Biology/ physics medicine, geophysics Electronics/ micromechanics 1970 Chemistry, machinery 1960 Car industry, Ship industry, civil eng, Aircraft industry Field of usage
Multiphysics A general purpose analysis tool allowing a user to combine the effects of two or more different, yet interrelated physics, within one, unified simulation environment. Electromagnetic Magnetic Thermal Fluid Electrostatic Electrical Structural
Machinery A general purpose analysis tool allowing a user to to combine the effects of two or more different, yet interrelated physics, within one, unified simulation environment Thermal Optimisation Interdistsiplinary Fluid Fatigue Dynamic Static Processes
Simulation Products Processis Forming Welding Contact problems
Applications Food industry T t t P t Spagetties drying process 2 2 2 = a11 T + a12 U + a13 P + U 2 2 = a T a U a 2 21 + 22 + 23 P 2 2 2 = a31 T + a32 U + a33 P P a 14 Q P pressure T Temperature U - humidity
Applications Process simulation welding
Applications Process simulation welding
FSI Remeshing Examples Coupled fluid-solid (FSI) meshing capability can handle applications with large boundary/domain changes. This feature addresses a broader range of FSI market applications, as the solid can undergo large deformation or even complete rotations. E.g.. Pumps or stirrers. Detached solid object can also move through the fluid. Example: Rigid body rotation, a flap valve in a tube:
FSI Detached, Moving Solid Example Cylinder passing through a channel:
Applications Process simulation Deep drawing
Applications Process simulation bending
Structural-Radiation Heat Transfer Coupling Radiation heat transfer to plate (temperature) Heated roller displacement versus time
Conjugate Heat Transfer Vertical heat sink
Thermal Structural Example BGA IC Package differential thermal expansion Image courtesy of MCR.
Applications Optimisation (topology and geometry) Applying simulation technology to industrial design accelerates the generation of design concepts that are exciting, feasible, desirable and profitable. Dave Simmon Altair Engineering, product innovation
Lokale Optimalitätskriterien Mattheck s Computer-Aided Optimization CAO Claus Mattheck leitet aus Beobachtungen des Wachstums von Bäumen, speziell ihrer Anpassung an unterschiedliche Belastungen, Optimierungsmethoden für grösste Belastbarkeit ab. Die Steigerung der Belastbarkeit folgt aus dem Abbau von lokalen Kerbwirkungen. Claus Mattheck, Design in der Natur, Rombach Wissenschaft, 1993
Optimisation
Probabilistic Design Random input parameters Material Properties Finite-Element Model Random output parameters Critical Stress Critical Strain Critical Temperature Lifetime... Probabilistic Results Loads Thermal Structural Geometry/ Tolerances equency Histogram Rel. Fre 0.18 0.16 0.14 0.12 0.10 0.08 0.06 0.04 0.02 0.00 35 30 5.1 7.1 9.0 Histogram 10.9 12.8 14.7 16.7 18.6 20.5 22.4 24.3 LN_LCF Scatter Plot ANSYS 26.3 28.2 30.1 32.0 Probability Cumulative Distribution Function 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% ANSYS 0 5 10 15 20 25 30 35 LN_LCF ANSYS Sensitivities of LN_LCF AN SYS Geometry Thermal BC 25 15 Boundary 10 Conditions 5 Gaps 0 Restraints LN_LCF 20 0 1 2 3 4 5 6 LN_STRESS Material
Applications Process simulation (hydroforming) Alcan Technology & Management AG
Applications Medizinstechnik Verbreiten den Blutgefäße StentFomMovie.mpeg
http://www.idac.co.uk/consulting/casestudies/depuy2/csdepuy2.htm
Applications Biomechanik (biologische trägestrukturen) http://www.uni-saarland.de/fak8/bi13wn/zoologie/
Applications Herz contact
Applications Fatigue Crack propagation area Kolben high temperature fatigue analysis Calculated life contours
Applications Scheibenbremse: Temperaturen Einfluss und Materialien Festigkeit
Auf die Felgen auftretende Lasten Applications http://www.simtop.fhg.de/cgi-bin/rmcat?1000hz01
Applications http://www.idac.co.uk/consulting/casestudies/londoneye/cs_londoneye.htm
LF Electromagnetic Cyclic Symmetry
Rotating Machine Examples Picture: CAD-FEM GmbH.
Acoustics Example Response of axisymmetric disc in tube to plane wave.
Fluid dynamics Pressure Iso lines Temperature
Applications Process in car engine
Applications Aerodynamics
Applications Crash 1995 15000 elements 1998 82000 elements 2000 160000 elements
3D Lagrange Interactions - External Gap Boing 747 Impact into a Reinforced Concrete Wall 3m thick wall 1m thick wall Courtesy of CRC Solutions, Tokyo, Japan
3D Lagrange Interactions - External Gap Phantom Jet Impact On Concrete Sandia Test, 1988 Courtesy Sandia National Lab.
3D Lagrange Interactions - External Gap Train Crash on thr JR- West s Fukuchiyama Line (Japan 2005) Condominium Building Impacted Column Impact Direction 90 Front = 45 Rear 2nd Car Courtesy of CRC Solutions, Tokyo, Japan
Applications
Applications
Applications Penetrations simulation http://www.hks.com /products /p_app_plate -impact.html
Applications Nonlinear analysis: Deformations in Rubber
Applications Acustics: Soundpressure inside car http:// www.apex-technologies.fr/applicat.htm
Rechnerische Ziele Reducing time for Simulations: Modeling, Meshing & Analysis time (John Swanson, 1997) Ansys Inc. 1980 Months 1994 Days 1996 Hours 2000 Minutes Ziel - 10 M DOF während 1Std
Computig time versus number of CPU AMG Performance (0.8 M DOF) Time (Sec c) 800 700 600 500 400 300 200 100 0 728.9 438.7 241.6 157 0 2 4 6 8 10 Number of Processors
You ve spent three days building a model, a day applying boundary conditions, and, after an overnight solution, you re ready to postprocess the results and move on to your next analysis. What s wrong with this picture? The problem is that we often don t spend enough time reviewing the answers and gaining insight into the problem to offer an enlightened interpretation of what the results really mean. John Crawford Consulting Analyst
Ein kleines Beispiel: Ein junger Ingenieur hat ein schönes FE-Modell erstellt. Er hat die Lastfälle und die Randbedingungen eingeben und das ganze laufen lassen. Wunderschöne farbige Bilder mit Spannungen sind herausgekommen. Es gab auch kritische Stellen welche sofort näher untersucht wurden. Sind sie wirklich kritisch oder liegt ein Modellierproblem vor? Irgendwann haben wir dann die Ergebnisse gemeinsam angeschaut. Seltsamerweise waren die Spannung etwas asymmetrisch obwohl ein symmetrischer Lastfall vorlag. Er konnte sich das auch nicht erklären und hat auch keinen Fehler im Modell gefunden. Als wir dann ein paar einfache Grundüberprüfungen machten, welcher er bisher nicht kannte, mussten wir feststellen, dass irgend eine horizontale Kraft auftrat, welche er aber nirgends aufbrachte. Eine weitere Untersuchung führte dann den Fehler zum Vorschein. Er hat im Modell die Erdanziehung mitrechnen lassen, nur leider war sein Modell um 90 gegenüber der Erdanziehung gedreht.
Engineers can t do a better job designing products just by working harder or longer hours, they need the right tools to leverage their expertise, and that demands investment in the latest software technology. David Weisberg Chief Industry Strategist Cyon Research Corp
Trends Better algorithms Better computers Bigger models (number of DOF) Assembly based (product) simulation Virtual Reality
Kvant computer RSA kood murtakse 5 minutit peale esimese suure kvantarvuti käivitamist David Deutsch (kvantarvutite guru) RSA Tuntuim avaliku võtmega krüptoalgoritm, mida loetakse turvaliseks alates 768 või 1024 biti pikkusest võtmest. Töötasid välja Rivest, Shamir ja Adleman 1978.a.
Virtual reality Physical based Simulation and Visualization of Flexible Materials for Design and Assembly Virtual Environments Research, Bonn; Fraunhofer IMK, Sankt Augustin
Assambly based analysis
Testing (CAT) There is need for testing for different products according to EU directives (lifters, Seat Frame with 3-point Safety Belt,...) Can rise the speed of investigation in some cases (incremental forming)
Testing
Testing
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