Texts on this page have been partially machine translated from German.

Research

Shape optimisation on an open-end spanner

Expertise: Mechanics, biomechanics, numerics

Optimisation in mechanics:

  • Structural optimisation, topology optimisation
  • Load and fatigue analysis: plastic collapse, short-term fatigue (LCF), ratchetting, toughening fracture mechanics
  • Structural reliability: First and Second Order Reliability Method (FORM/SORM), probabilistic fracture mechanics, stochastic optimisation
  • Material modelling: Identification and parameter estimation

Optimisation in biomechanics:

  • Functional adaptation: soft and hard tissue, bone remodelling
  • Biomechanical multi-body systems (MBS): calculation of muscle and joint forces, rehabilitation, sports biomechanics, ergonomics, accident biomechanics
  • Models of biological materials: identification and parameter estimation

What we offer:

  • Consultancy, studies and development of methods and software for our main research areas (partly under construction)
  • Many years of experience in the fields of finite element method (FEM), material theory, load and load deflection analysis in structural and fracture mechanics
  • Experience as a partner and coordinator of European and national projects and studies with industrial partners, universities and research institutes
  • Our collaboration in research and development projects in mechanics and its border areas

In the past, scientific and technical problems had to be modelled in such an idealised and simplified way that they could be solved. This changed with the development of numerical methods such as the finite element method (FEM). The area to be calculated is constructed from finite elements as if using Lego bricks. These building blocks are so simple that their solution is known. The overall solution is built up from the individual solutions.

The rapid development of computer science today allows very detailed solutions with millions of finite elements. Such a large construction kit can only be handled with high performance computing. In addition, it has been successfully recognised that many problems are non-linear and that different effects often act simultaneously. While structure, flow and temperature were initially modelled separately, today they are increasingly being calculated in combination. In times of global competition and scarce resources, the question of the best solution is becoming increasingly interesting. Such optimisation problems can only be solved for relatively small problem sizes.

In a European research project, we are combining non-linear FEM with optimisation. We are investigating the maximum load-bearing capacity of structures, machines and apparatus. The example of a highly stressed compressor disc from the company DEMAG DELAVAL, Duisburg, will be exhibited. A higher load-bearing capacity allows higher speeds with better efficiency. This creates competitive advantages and protects the environment.

Graphische Darstellung Verdichter

FH AACHEN | Labor Biomechanik

Verdichter

FH AACHEN | Labor Biomechanik

In a European research project, we combine non-linear FEM with optimisation. We are investigating the maximum load-bearing capacity of structures, machines and apparatus. The example of a highly stressed compressor disc from the company DEMAG DELAVAL, Duisburg, will be exhibited. A higher load-bearing capacity allows higher speeds with better efficiency. This creates competitive advantages and protects the environment.

Projects:

  • Competition of the State of North Rhine-Westphalia; Translational Stem Cell Research" (2014) Project CardiacDrums: Measurement of mechanical baseline stresses and beat amplitudes of hiPS-based cardiomyocytes for functional drug and toxin testing in personalised medicine. 01.08.2014-31.12.2015. Reference number: z1403ts021b.
  • FHprofUNT2012 Project BINGO: Optimisation of the mesh implant-pelvic floor system for therapeutic tissue reinforcement according to the integral theory. 01.01.2013-31.12.2015, funding reference: 03FH073PX2.
  • ZIM project: Adjustable alloplastic sling system for minimally invasive treatment of stress incontinence in women, 2010-2011, funding code: KF 2545602AJ9.
  • EU Leonardo Project WEBD: Web based training of biomedical specialists. 2009-2010, Grant Agreement Reference No.: 2008-1-TRI-LE005-03241.
  • EU Brite-EuRam Project LISA: FEM-based Limit and Shakedown Analysis for Design and Integrity Assessment in European Industry. January 1, 1998 to May 31, 2002, Contract No. BRPR-CT97-0595, Project No. BE 97-4547.

Co-operations:

  • Companies: INTES, Stuttgart, Siemens/Framatome ANP, Erlangen, Demag Delaval/Siemens , Duisburg, FEV, Aachen, Electricité de France (EDF), Bureau Veritas, Paris, NEC, St. Augustin
  • Universities: Chemnitz, Duisburg-Essen, RWTH Aachen, Sherbrooke (CA), Liège (BE)
  • Research centres: Jülich, Geesthacht
  • Ford Research Centre Aachen

Further information on the...

Biomechanics

Biomechanics is the application of mechanics to the musculoskeletal system, organs, tissue and cells. It has many applications in the medical field.

Biological systems adapt independently to their mechanical requirements. Biological optimisation methods can be transferred to technical systems. Conversely, mathematical optimisation methods are tested in technology and applied to biological systems.

Optimisation in biomechanics:

  • Functional adaptation: soft and hard tissue, bone remodelling
  • Biomechanical multi-body systems (MBS): calculation of muscle and joint forces, rehabilitation, sports biomechanics, ergonomics, accident biomechanics
  • Modelling of biological materials: identification and parameter estimation



Poster download (selection)

Shape optimisation with the help of finite element methods

CAO - Computer Aided Optimisation
M. Stroh, K.-H. Gatzweiler, M. Staat, S. Sponagel

> download A4 poster as PDF file ...

Calculation of joint forces caused by riding an exercise bike

J. Leemann1), K.-H. Gatzweiler1), E. Schopphoff2), M. Staat1)1)Biomechanics Laboratory, Aachen University of Applied Sciences, Division Jülich2)Chair for Mechanics, University of Duisburg-Essen

> download A4 poster as PDF file...

Pressure distribution measurement on the foot

Diagnosis of healthy and diseased feet - gait analysis C. Weil, K.-H. Gatzweiler, M. Staat, S. Sponagel

> download A4 poster as PDF file

 

Experimental investigation of rebound resilience and attenuation of falls using hip protectors and testing in accordance with DIN 53 512

M. Staat1), K.-H. Gatzweiler1), A. Chafik1)
on behalf of F. W. Koch2)

1) Biomechanics Laboratory, Aachen University of Applied Sciences, Jülich Division
2) i-care Koch GmbH www.i-care-ac.de

> download A4 poster as PDF file



Doctoral theses:

  1. W. Senger: Mechanics of bone remodelling around implants, doctoral thesis, RWTH Aachen University, 1993.
  2. S. Kühn: A theory of biological growth processes. doctoral thesis, TU Darmstadt, 1997.

Publications:

  1. J. Rausch, K. Siebertz, M. Staat: Biomechanical Models to Evaluate Comfort. EUROFORUM Conference "Automotive Interiors", Munich, 15-16 February 2006.
  2. R. Kühn, W. Hauger, M. Staat, S. Sponagel: A Two Phase Mixture Model Based on Bone Observation, PAMM - Proceedings in Applied Mathematics and Mechanics, 4 (1), (2004) 618-619.
  3. R. Kühn, W. Hauger, S. Sponagel, M. Staat: An Interpretation of Wolff's Law, Biomedical Engineering, 49, Supplementary Volume 2, Part 2, (2004) 1020-1021.
  4. G. Baroud, J. Wu, M. Bohner, S. Sponagel, T. Steffen: How to determine the permeability for cement infiltration into osteoporotic cancellous bone. Medical Engineering & Physics, 25 (4), (2003) 283-288.
  5. G. Baroud, T. Steffen, J. Wu, S. Sponagel: Parameter identification for cement infiltration of osteoporotic bone. In J.L. Auriault, et al. (eds.): Poromechanics II, Proceedings of the Second Biot Conference on Poromechanics, Balkema at Swets & Zeitlinger, Lisse (NL) 2002, 55-58.

Material theory

Plasticity, damage mechanics, rheology of multiphase systems

Doctoral theses:

  1. M. Staat: Nonlinear waves in elastic discs. Doctoral thesis, RWTH Aachen University, 1987.
  2. S. Sponagel: Rubber-metal components. Dr.-Ing. doctoral thesis, University of Kaiserslautern, 1987.
  3. S. Sponagel: On the stability of a simple viscometric movement. Dr rer. nat. doctoral thesis, TU Darmstadt, 1982.

Publications:

  1. U. Akbay, E. Becker, S. Krozer, S. Sponagel: Instability of slow viscometric flow , Mech. Res. Commun., 7(4) (1980) 199-204.
  2. U. Akbay, E. Becker, S. Krozer, S. Sponagel: A possible cause of viscoelastic turbulence G. Astarita (ed.) Proc. 8th Int. Congr. on Rheology, Naples, September 1 - 5, 1980 Vol. 2, Plenum Pr., New York (1980) 79-84.
  3. U. Akbay, S. Sponagel: On the stability of viscometric flows , Rheol. Acta. 20 (1981) 579-590.
  4. S. Sponagel, U. Akbay. On the mechanism of surface instability of viscometric flows, Rheologica Acta, 23 (2) (1984), 185-188.
  5. J. Ballmann, H.J. Raatschen, M. Staat: High Stress Intensities in Focussing Zones of Waves. In P. Ladeveze (Ed.): Local Effects in the Analysis of Structures. Elsevier, Amsterdam (1985).
  6. M. Staat, J. Ballmann: Anisotropic propagation and focussing of acceleration waves in pre-stressed non-linear elastic discs. In: Wave focussing, Colloquium of the SFB 27, RWTH Aachen (1985) 140-158.
  7. U. Akbay, E. Becker, S. Sponagel: Instability of plane Couette flow of viscoelastic liquids , J. Non-Newtonian Fluid Mechanics, 18 (1985) 123-141.
  8. S. Sponagel: Analytical calculation of rubber-metal joints . Konstruktion - Zeitschrift für Produktentwicklung 36 (4) (1987) 151-158.
  9. M. Staat: Anisotropic wave propagation in isotropic hyperelastic discs ZAMM - Zeitschrift für Angewandte Mathematik und Mechanik, 67 (1987) T241-T243.
  10. J. Ballmann, M. Staat: Computation of Impacts on Elastic Solids by Methods of Bicharacteristics. In S.N. Atluri, G. Yagawa (Eds.): Computational Mechanics '88, Theory and Applications. Vol. 2, Springer, Berlin (1988) Chap. 60.i.1-i.4.
  11. J. Ballmann, M. Staat: Wave Propagation and Focussing in Plates. In C.Y. Chiem, H.D. Kunze, L.W. Meyer (Eds.): Impact Loading and Dynamic Behaviour of Materials. Vol. 2, Deutsche Gesellschaft für Metallkunde Informationsgesellschaft, Oberursel (1988).
  12. M. Staat, J. Ballmann: On the problem of tensorial generalisations of uniaxial nonlinear material laws, ZAMM - Zeitschrift für Angewandte Mathematik und Mechanik, 69 (1989) 73-81.
  13. M. Staat, J. Ballmann: Fundamental Aspects of Numerical Methods for the Propagation of Multidimensional Nonlinear Waves in Solids. In J. Ballmann, R. Jeltsch (Eds.): Nonlinear Hyperbolic Equations- Theory, Computation Methods, and Applications. Vieweg, Braunschweig (1989) 574-588.
  14. S. Sponagel, Th. Lutz: A contribution to the determination of the hardness values of elastomers, Kautschuk Gummi Kunststoffe, 43 (10), (1990) 861-865.
  15. G. Baroud, T. Steffen, J. Wu, S. Sponagel: Parameter identification for cement infiltration of osteoporotic bone. In J.L. Auriault, et al. (eds.): Poromechanics II, Proceedings of the Second Biot Conference on Poromechanics, Balkema at Swets & Zeitlinger, Lisse (NL) 2002, 55-58.
  16. M. Staat, M. Heitzer: The restricted influence of kinematic hardening on shakedown loads. Proceedings of WCCM V, 5th World Congress on Computational Mechanics, Vienna, Austria, July 7-12, 2002. opus. bibliothek.fh-aachen.de/opus/volltexte/2005/79/
  17. G. Baroud, T. Steffen, J. Wu, S. Sponagel: Parameter identification for cement infiltration of osteoporotic bone. In J.L. Auriault, et al. (eds.): Poromechanics II, Proceedings of the Second Biot Conference on Poromechanics, Balkema at Swets & Zeitlinger, Lisse (NL) 2002, 55-58.
  18. G. Baroud, J. Wu, M. Bohner, S. Sponagel, T. Steffen: How to determine the permeability for cement infiltration into osteoporotic cancellous bone. Medical Engineering & Physics, 25 (4), (2003) 283-288. dx. doi.org/10.1016/S1350-4533(02)00223-0
  19. S. Sponagel, J. Unger, K. H. Spies: Hardness concept in connection with cross-linking, elongation at break and fatigue strength of an elastomer. KGK - Kautschuk Gummi Kunststoffe, 56 (11), (2003) 608-613.
  20. Duc Khoi Vu, M. Staat: An Algorithm for Shakedown Analysis for Materials with Temperature Dependent Yield Stress. PAMM - Proceedings in Applied Mathematics and Mechanics, 4 (1), (2004) 231-233. dx. doi.org/10.1002/pamm.200410097

Load capacity and play-in analysis

Proofs of safety, theory, numerics, stochastics

Doctoral theses:

  • T. N. Tran:: Limit and Shakedown Analysis of Thin Plates and Shells, Including Uncertainty. doctoral thesis, TU Chemnitz (started).
  • M. Heitzer: Load and shakedown analysis for calculating the safety of passive components. Doctoral thesis, RWTH Aachen, 1999

Book:

M. Staat, M. Heitzer: (Eds.): Numerical Methods for Limit and Shakedown Analysis. Deterministic and Probabilistic Approach. NIC Series Vol. 15, John von Neumann Institute for Computing, Jülich (2003). www.fz-juelich.de/nic-series/volume15/nic-series-band15.pdf

Other publications:

  1. M. Staat, M. Heitzer: Limit and Shakedown Analysis Using a General Purpose Finite Element Code. Proceedings of the NAFEMS World Congress '97, Stuttgart, 522-533.
  2. M. Staat, M. Heitzer: Limit and Shakedown Analysis for Plastic Safety of Complex Structures. SMiRT 14 Transactions Vol. B, Lyon, France (1997) B02/2.
  3. M. Staat, M. Heitzer: Limit and shakedown analysis for design. Proceedings of 7th German-Japanese Joint Seminar on Research in Structural Strength and NDE-Problems in Nuclear Engineering, MPA Stuttgart, September 1997, 4.3.1-4.3.19.
  4. M. Staat, M. Heitzer: Direct FEM calculation of the load-bearing capacity of highly stressed passive components. 23rd MPA Seminar, Stuttgart, October 1997, 29.1-29.19.
  5. M. Staat, M. Heitzer, E.F. Hicken: LISA, a European project for the direct calculation of the load-bearing capacity of ductile structures. PERMAS User Conference, 8-9 October 1998, Stuttgart (1998).
  6. M. Heitzer, M. Staat: FEM-computation of load carrying capacity of highly loaded passive components by direct methods. Nuclear Engineering and Design, 193 (1999) 349-358. dx. doi.org/10.1016/S0029-5493(99)00190-9
  7. M. Heitzer, M. Staat: Structural Reliability Analysis of Elasto-Plastic Structures. In G.I. Schuëller, P. Kafka (eds.) Safety and Reliability, A. A. Balkema, Rotterdam (1999) 513-518.
  8. M. Staat, M. Heitzer: LISA - a European project for FEM-based ultimate load and load deflection analysis. 25th MPA Seminar, Stuttgart, 6 and 7 October 1999, 10.1-10.20.
  9. H. Lang, K. Wirtz, M. Heitzer, M. Staat, R. Oettel: Cyclic load tests for the verification of shakedown analyses using FEM. 25th MPA Seminar, Stuttgart, 6 and 7 October 1999, 44.1-44.18.
  10. M. Heitzer, M. Staat: Ultimate load analysis - a structural-mechanical method for the assessment of cracked components and connections. DVM Report 232: Strength and fracture behaviour of joints, Berlin (2000) 183-192.
  11. M. Staat, M. Heitzer, Yan Ai-Min, Khoi Vu Duc, Nguyen-Dang Hung, F. Voldoire, A. Lahousse: Limit Analysis of Defects. Report of the Research Centre Jülich, Jül-3746 (2000).
  12. M. Heitzer, M. Staat: Direct FEM approach to design-by-analysis of pressurised components. ACHEMA 2000, Frankfurt/Main (2000) 79-81.
  13. M. Heitzer, M. Staat: Direct static FEM approach to limit and shakedown analysis. CD-ROM Proceedings of the Fourth International Colloquium on Computation of Shell & Spatial Structures, IASS-IACM 2000, Chania, Crete, Greece (2000), paper 058, 14 pages. opus. bibliothek.fh-aachen.de/opus/volltexte/2005/80/
  14. M. Heitzer, M. Staat: Direct FEM Limit and Shakedown Analysis with Uncertain Data. CD-ROM Proceedings of the European Congress on Computational Methods in Applied Sciences and Engineering, ECCOMAS 2000, Barcelona, Spain (2000), paper 483, 13 pages. opus. bibliothek.fh-aachen.de/opus/volltexte/2006/112/
  15. M. Heitzer, M. Staat: Reliability Analysis of Elasto-Plastic Structures under Variable Loads. In G. Maier, D. Weichert (Eds.): Inelastic Analysis of Structures under Variable Loads: Theory and Engineering Applications, Kluwer, Academic Press, Dordrecht (2000) 269-288.
  16. M. Heitzer, G. Pop, M. Staat: Basis reduction for the shakedown problem for bounded kinematic hardening material. Journal of Global Optimisation, 17 (2000) 185-200. dx. doi.org/10.1023/A:1008321026063
  17. M. Staat, M. Heitzer: LISA a European Project for FEM-based Limit and Shakedown Analysis. Nuclear Engineering and Design, 206 (2001) 151-166. dx. doi.org/10.1016/S0029-5493(00)00415-5
  18. H. Lang, K. Wirtz, M. Heitzer, M. Staat, R. Oettel: Cyclic Plastic Deformation Tests to Verify FEM-Based Shakedown Analyses. Nuclear Engineering and Design, 206 (2001) 227-239. http://dx.doi.org/10.1016/S0029-5493(00)00438-6
  19. M. Staat, E. Szelinski, M. Heitzer: Collapse analysis of longitudinally flawed pipes and vessels. 27th MPA Seminar: Safety and Availability in Plant Engineering, Stuttgart (2001) 4.1-4.20.
  20. M. Heitzer, H. Reinders, F. Schubert, M. Staat: Shakedown and Ratchetting under Tensile and Torsional Loading: Analysis and Experiments. 27th MPA Seminar: Safety and Availability in Plant Engineering, Stuttgart (2001) 24.1.-24.16.
  21. M. Heitzer, M. Staat: Limit and Shakedown Analysis with Uncertain Data. In: K. Marti (Ed.) Stochastic Optimisation Techniques, Numerical Methods and Technical Applications, Lecture Notes in Economics and Mathematical Systems, Vol. 513, Springer. Heidelberg (2002) 241-254 (253-267).
  22. M. Staat, M. Heitzer: The restricted influence of kinematic hardening on shakedown loads. Proceedings of WCCM V, 5th World Congress on Computational Mechanics, Vienna, Austria, July 7-12, 2002. opus. bibliothek.fh-aachen.de/opus/volltexte/2005/79/
  23. M. Staat: Some Achievements of the European Project LISA for FEM Based Limit and Shakedown Analysis. In N. Badie (ed.) Computational Mechanics: Developments and Applications - 2002. ASME PVP Vol. 441, Paper PVP2002-1300, pp.177-185 (2002). store. asme.org/product.asp?catalog%5Fname=Conference+Papers&category%5Fname=&product%5Fid=PVP2002%2D1300
  24. M. Heitzer, M. Staat: Basis reduction technique for limit and shakedown problems. In M. Staat, M. Heitzer: (Eds.): Numerical Methods for Limit and Shakedown Analysis. Deterministic and Probabilistic Approach. NIC Series Vol. 15, John von Neumann Institute for Computing, Jülich (2003) pp.1-55. www.fz-juelich.de/nic-series/volume15/nic-series-band15.pdf
  25. M. Staat, M. Heitzer: Probabilistic limit and shakedown problems. In M. Staat, M. Heitzer: (Eds.): Numerical Methods for Limit and Shakedown Analysis. Deterministic and Probabilistic Approach. NIC Series Vol. 15, John von Neumann Institute for Computing, Jülich (2003) pp.217-268. www.fz-juelich.de/nic-series/volume15/nic-series-band15.pdf
  26. M. Staat, M. Schwartz, H. Lang, K. Wirtz, M. Heitzer: Design by Analysis of Pressure Components by Non-linear Optimisation. In: J.L. Zeman (Ed.) Pressure Vessel Technology 2003, Proceedings ICPVT-10, July 7-10, 2003 Vienna, Austria, ÖGS, Österreichische Gesellschaft für Schweißtechnik, Vienna, 59-65. http://opus.bibliothek.fh-aachen.de/opus/volltexte/2005/93/
  27. M. Heitzer, M. Staat, H. Reiners, F. Schubert: Shakedown and ratchetting under tension-torsion loadings: analysis and experiments. Nuclear Engineering and Design, 225 (2003) 11-26. http://dx.doi.org/10.1016/S0029-5493(03)00134-1
  28. M. Staat: Plastic collapse analysis of longitudinally flawed pipes and vessels. Nuclear Engineering and Design, 234/1-3, (2004) 25-43. dx. doi.org/10.1016/j.nucengdes.2004.08.002
  29. Duc Khoi Vu, M. Staat: An Algorithm for Shakedown Analysis for Materials with Temperature Dependent Yield Stress. PAMM - Proceedings in Applied Mathematics and Mechanics, 4 (1), (2004) 231-233. dx. doi.org/10.1002/pamm.200410097
  30. M. Staat, M. Heitzer, H. Lang, K. Wirtz: Direct Finite Element Route for Design-by-Analysis of Pressure Components. Int. J. Pressure Vessels Piping, 82 (2005) 61-67. dx. doi.org/10.1016/j.ijpvp.2004.04.006
  31. M. Staat: Local and global collapse pressure of longitudinally flawed pipes and cylindrical vessels. Int. J. Pressure Vessels Piping, 82/3(2005) 217-225. dx. doi.org/10.1016/j.ijpvp.2004.07.022
  32. M. Staat, Duc Khoi Vu: Limit loads of circumferentially flawed pipes and cylindrical vessels under internal pressure, Int. J. Pressure Vessels Piping, 2005 accepted.

Fracture mechanics

Plastic collapse, probabilistic fracture mechanics

Publications:

  1. M. Staat: Probabilistic assessment of the fracture mechanics behaviour of the primary circuit pressure boundary of an HTR module. In: 18th MPA Seminar: Safety and Availability in Plant Engineering. Stuttgart (1992) 27.1-27.18.
  2. M. Staat: Failure Probabilities of the Primary Circuit Pressure Boundary of an HTR-Module for Process Heat Generation under Accident Conditions for Different Failure Modes. Nuclear Engineering and Design 144 (1993) 53-67. dx. doi.org/10.1016/0029-5493(93)90008-W
  3. M. Staat: Reliability of the Primary Circuit Pressure Boundary of an HTR-Module under Accident Conditions. In P. Kafka (Ed.): Safety and Reliability Assessment. An Integral Approach. Elsevier, Amsterdam (1993) 331-342.
  4. M. Staat: Sensitivity of and Influences on the Reliability of an HTR-Module Primary Circuit Pressure Boundary. SMiRT 12 Transactions Vol. M, Stuttgart, Germany, paper MG10/2 (1993) 147-152.
  5. M. Staat: Reliability of an HTR-Module Primary Circuit Pressure Boundary: Influences, Sensitivity, and Comparison with a PWR. Nuclear Engineering and Design, 158 (1995) 333-340. dx. doi.org/10.1016/0029-5493(95)01040-O
  6. M. Staat: Probabilistic Assessment of the Fracture Mechanical Behaviour of an HTR-Module Primary Circuit Pressure Boundary. Nuclear Engineering and Design, 160 (1996) 221-236. dx. doi.org/10.1016/0029-5493(95)01105-6
  7. M. Staat: Problems and Chances for Probabilistic Fracture Mechanics in the Analysis of Steel Pressure Boundary Reliability. In: Technical feasibility and reliability of passive safety systems for nuclear power plants. Proceedings of an Advisory Group Meeting held in Jülich, 21-24 November 1994, IAEA-TECDOC-920, Vienna, December 1996, 43-55.
  8. M. Heitzer, M. Staat: Ultimate load analysis - a structural-mechanical method for the assessment of cracked components and connections. DVM Report 232: Strength and fracture behaviour of joints, Berlin (2000) 183-192.
  9. M. Staat, M. Heitzer, Yan Ai-Min, Khoi Vu Duc, Nguyen-Dang Hung, F. Voldoire, A. Lahousse: Limit Analysis of Defects. Report of the Research Centre Jülich, Jül-3746 (2000).
  10. M. Staat, E. Szelinski, M. Heitzer: Collapse analysis of longitudinally flawed pipes and vessels. 27th MPA Seminar: Safety and Availability in Plant Engineering, Stuttgart (2001) 4.1-4.20.
  11. M. Staat: Plastic collapse analysis of longitudinally flawed pipes and vessels. Nuclear Engineering and Design, 234/1-3, (2004) 25-43. dx. doi.org/10.1016/j.nucengdes.2004.08.002
  12. M. Staat: Local and global collapse pressure of longitudinally flawed pipes and cylindrical vessels. Int. J. Pressure Vessels Piping, 82/3(2005) 217-225. dx. doi.org/10.1016/j.ijpvp.2004.07.022
  13. M. Staat, Duc Khoi Vu: Limit loads of circumferentially flawed pipes and cylindrical vessels under internal pressure, Int. J. Pressure Vessels Piping, 2005 accepted.

Apparatus engineering

Design-by-Analysis, Failure Assessment

Doctoral theses:

  • T. N. Tran: Limit and Shakedown Analysis of Thin Plates and Shells, Including Uncertainty. doctoral thesis, TU Chemnitz (started).
  • M. Heitzer: Ultimate load and shakedown analysis for calculating the safety of passive components. doctoral thesis, RWTH Aachen University, 1999. doctoral thesis, RWTH Aachen University, 1999

Publications:

  1. M. Staat, M. Heitzer: Limit and shakedown analysis for design. Proceedings of 7th German-Japanese Joint Seminar on Research in Structural Strength and NDE-Problems in Nuclear Engineering, MPA Stuttgart, September 1997, 4.3.1-4.3.19.
  2. M. Staat, M. Heitzer: Direct FEM calculation of the load-bearing capacity of highly stressed passive components. 23rd MPA Seminar, Stuttgart, October 1997, 29.1-29.19.
  3. M. Heitzer, M. Staat: Ultimate load analysis - a structural-mechanical method for the assessment of cracked components and connections. DVM Report 232: Strength and fracture behaviour of joints, Berlin (2000) 183-192.
  4. M. Staat, M. Heitzer, Yan Ai-Min, Khoi Vu Duc, Nguyen-Dang Hung, F. Voldoire, A. Lahousse: Limit Analysis of Defects. Report of the Research Centre Jülich, Jül-3746 (2000).
  5. M. Heitzer, M. Staat: Direct FEM approach to design-by-analysis of pressurised components. ACHEMA 2000, Frankfurt/Main (2000) 79-81.
  6. M. Staat, E. Szelinski, M. Heitzer: Collapse analysis of longitudinally flawed pipes and vessels. 27th MPA Seminar: Safety and Availability in Plant Engineering, Stuttgart (2001) 4.1-4.20.
  7. H. Lang, K. Wirtz, M. Heitzer, M. Staat, R. Oettel: Cyclic Plastic Deformation Tests to Verify FEM-Based Shakedown Analyses. Nuclear Engineering and Design, 206 (2001) 227-239. http://dx.doi.org/10.1016/S0029-5493(00)00438-6
  8. M. Staat: Some Achievements of the European Project LISA for FEM Based Limit and Shakedown Analysis. In N. Badie (ed.) Computational Mechanics: Developments and Applications - 2002. ASME PVP Vol. 441, Paper PVP2002-1300, pp.177-185 (2002). store. asme.org/product.asp?catalog%5Fname=Conference+Papers&category%5Fname=&product%5Fid=PVP2002%2D1300
  9. M. Staat, M. Schwartz, H. Lang, K. Wirtz, M. Heitzer: Design by Analysis of Pressure Components by Non-linear Optimisation. in: J.L. Zeman (Ed.) Pressure Vessel Technology 2003, Proceedings ICPVT-10, July 7-10, 2003 Vienna, Austria, ÖGS, Österreichische Gesellschaft für Schweißtechnik, Vienna, 59-65. http://opus.bibliothek.fh-aachen.de/opus/volltexte/2005/93/
  10. M. Heitzer, M. Staat, H. Reiners, F. Schubert: Shakedown and ratchetting under tension-torsion loadings: analysis and experiments. Nuclear Engineering and Design, 225 (2003) 11-26. http://dx.doi.org/10.1016/S0029-5493(03)00134-1
  11. M. Staat: Plastic collapse analysis of longitudinally flawed pipes and vessels. Nuclear Engineering and Design, 234/1-3, (2004) 25-43. dx. doi.org/10.1016/j.nucengdes.2004.08.002
  12. Duc Khoi Vu, M. Staat: An Algorithm for Shakedown Analysis for Materials with Temperature Dependent Yield Stress. PAMM - Proceedings in Applied Mathematics and Mechanics, 4 (1), (2004) 231-233. dx. doi.org/10.1002/pamm.200410097
  13. M. Staat, M. Heitzer, H. Lang, K. Wirtz: Direct Finite Element Route for Design-by-Analysis of Pressure Components. Int. J. Pressure Vessels Piping, 82 (2005) 61-67. dx. doi.org/10.1016/j.ijpvp.2004.04.006
  14. M. Staat: Local and global collapse pressure of longitudinally flawed pipes and cylindrical vessels. Int. J. Pressure Vessels Piping, 82/3(2005) 217-225. dx. doi.org/10.1016/j.ijpvp.2004.07.022
  15. M. Staat, Duc Khoi Vu: Limit loads of circumferentially flawed pipes and cylindrical vessels under internal pressure, Int. J. Pressure Vessels Piping, 2005 accepted.

reliability

Structural reliability, FORM/SORM, Monte Carlo methods

doctoral theses:

  • T. N. Tran: Limit and Shakedown Analysis of Thin Plates and Shells, Including Uncertainty, doctoral thesis, TU Chemnitz (started).
  • M. Heitzer: Ultimate load and shakedown analysis for calculating the safety of passive components. doctoral thesis, RWTH Aachen University, 1999

Book:

M. Staat, M. Heitzer: (Eds.): Numerical Methods for Limit and Shakedown Analysis. Deterministic and Probabilistic Approach. NIC Series Vol. 15, John von Neumann Institute for Computing, Jülich (2003). www.fz-juelich.de/nic-series/volume15/nic-series-band15.pdf

Other publications:

  1. J. Ballmann, H.J. Raatschen, M. Staat: High Stress Intensities in Focussing Zones of Waves. In P. Ladeveze (Ed.): Local Effects in the Analysis of Structures. Elsevier, Amsterdam (1985).
  2. M. Staat, J. Ballmann: Anisotropic propagation and focussing of acceleration waves in pre-stressed non-linear elastic discs. In: Wave focussing, Colloquium of the SFB 27, RWTH Aachen (1985) 140-158.
  3. M. Staat: Anisotropic wave propagation in isotropic hyperelastic discs , ZAMM - Zeitschrift für Angewandte Mathematik und Mechanik, 67 (1987) T241-T243.
  4. J. Ballmann, M. Staat: Computation of Impacts on Elastic Solids by Methods of Bicharacteristics. In S.N. Atluri, G. Yagawa (Eds.): Computational Mechanics '88, Theory and Applications. Vol. 2, Springer, Berlin (1988) Chap. 60.i.1-i.4.
  5. J. Ballmann, M. Staat: Wave Propagation and Focussing in Plates. In C.Y. Chiem, H.D. Kunze, L.W. Meyer (Eds.): Impact Loading and Dynamic Behaviour of Materials. Vol. 2, Deutsche Gesellschaft für Metallkunde Informationsgesellschaft, Oberursel (1988).
  6. M. Staat, J. Ballmann: Fundamental Aspects of Numerical Methods for the Propagation of Multidimensional Nonlinear Waves in Solids. In J. Ballmann, R. Jeltsch (Eds.): Nonlinear Hyperbolic Equations- Theory, Computation Methods, and Applications. Vieweg, Braunschweig (1989) 574-588.
  7. M. Staat, M. Heitzer: Limit and Shakedown Analysis Using a General Purpose Finite Element Code. Proceedings of the NAFEMS World Congress '97, Stuttgart, 522-533.
  8. M. Heitzer, M. Staat: Reliability Analysis of Elasto-Plastic Structures under Variable Loads. In G. Maier, D. Weichert (Eds.): Inelastic Analysis of Structures under Variable Loads: Theory and Engineering Applications, Kluwer, Academic Press, Dordrecht (2000) 269-288.
  9. M. Heitzer, G. Pop, M. Staat: Basis reduction for the shakedown problem for bounded kinematic hardening material. Journal of Global Optimisation, 17 (2000) 185-200. dx. doi.org/10.1023/A:1008321026063
  10. M. Heitzer, M. Staat: Basis reduction technique for limit and shakedown problems. In M. Staat, M. Heitzer: (Eds.): Numerical Methods for Limit and Shakedown Analysis. Deterministic and Probabilistic Approach. NIC Series Vol. 15, John von Neumann Institute for Computing, Jülich (2003) pp.1-55. www.fz-juelich.de/nic-series/volume15/nic-series-band15.pdf
  11. M. Staat, M. Heitzer: Probabilistic limit and shakedown problems. In M. Staat, M. Heitzer: (Eds.): Numerical Methods for Limit and Shakedown Analysis. Deterministic and Probabilistic Approach. NIC Series Vol. 15, John von Neumann Institute for Computing, Jülich (2003) pp.217-268. www.fz-juelich.de/nic-series/volume15/nic-series-band15.pdf
  12. Duc Khoi Vu, M. Staat: An Algorithm for Shakedown Analysis for Materials with Temperature Dependent Yield Stress. PAMM - Proceedings in Applied Mathematics and Mechanics, 4 (1), (2004) 231-233. dx. doi.org/10.1002/pamm.200410097

Numerical methods

FEM, nonlinear optimisation, stochastic optimisation, hyperbolic differential equations

Doctoral theses:

  • T. N. Tran: Limit and Shakedown Analysis of Thin Plates and Shells, Including Uncertainty. doctoral thesis, TU Chemnitz (started).
  • H. Heitzer: Load and shakedown analysis for calculating the safety of passive components, doctoral thesis, RWTH Aachen University, 1999.
  • M. Staat: Nonlinear waves in elastic discs. Doctoral thesis, RWTH Aachen University, 1987.

Book:

M. Staat, M. Heitzer: (Eds.): Numerical Methods for Limit and Shakedown Analysis. Deterministic and Probabilistic Approach. NIC Series Vol. 15, John von Neumann Institute for Computing, Jülich (2003). www.fz-juelich.de/nic-series/volume15/nic-series-band15.pdf

 

Other publications:

  1. J. Ballmann, H.J. Raatschen, M. Staat: High Stress Intensities in Focussing Zones of Waves. In P. Ladeveze (Ed.): Local Effects in the Analysis of Structures. Elsevier, Amsterdam (1985).
  2. M. Staat, J. Ballmann: Anisotropic propagation and focussing of acceleration waves in pre-stressed non-linear elastic discs. In: Wave focussing, Colloquium of the SFB 27, RWTH Aachen (1985) 140-158.
  3. M. Staat: Anisotropic wave propagation in isotropic hyperelastic discs , ZAMM - Zeitschrift für Angewandte Mathematik und Mechanik, 67 (1987) T241-T243.
  4. J. Ballmann, M. Staat: Computation of Impacts on Elastic Solids by Methods of Bicharacteristics. In S.N. Atluri, G. Yagawa (Eds.): Computational Mechanics '88, Theory and Applications. Vol. 2, Springer, Berlin (1988) Chap. 60.i.1-i.4.
  5. J. Ballmann, M. Staat: Wave Propagation and Focussing in Plates. In C.Y. Chiem, H.D. Kunze, L.W. Meyer (Eds.): Impact Loading and Dynamic Behaviour of Materials. Vol. 2, Deutsche Gesellschaft für Metallkunde Informationsgesellschaft, Oberursel (1988).
  6. M. Staat, J. Ballmann: Fundamental Aspects of Numerical Methods for the Propagation of Multidimensional Nonlinear Waves in Solids. In J. Ballmann, R. Jeltsch (Eds.): Nonlinear Hyperbolic Equations- Theory, Computation Methods, and Applications. Vieweg, Braunschweig (1989) 574-588.
  7. M. Staat, M. Heitzer: Limit and Shakedown Analysis Using a General Purpose Finite Element Code. Proceedings of the NAFEMS World Congress '97, Stuttgart, 522-533.
  8. M. Heitzer, M. Staat: Reliability Analysis of Elasto-Plastic Structures under Variable Loads. In G. Maier, D. Weichert (Eds.): Inelastic Analysis of Structures under Variable Loads: Theory and Engineering Applications, Kluwer, Academic Press, Dordrecht (2000) 269-288.
  9. M. Heitzer, G. Pop, M. Staat: Basis reduction for the shakedown problem for bounded kinematic hardening material. Journal of Global Optimisation, 17 (2000) 185-200. dx. doi.org/10.1023/A:1008321026063
  10. M. Heitzer, M. Staat: Basis reduction technique for limit and shakedown problems. In M. Staat, M. Heitzer: (Eds.): Numerical Methods for Limit and Shakedown Analysis. Deterministic and Probabilistic Approach. NIC Series Vol. 15, John von Neumann Institute for Computing, Jülich (2003) pp.1-55. www.fz-juelich.de/nic-series/volume15/nic-series-band15.pdf
  11. M. Staat, M. Heitzer: Probabilistic limit and shakedown problems. In M. Staat, M. Heitzer: (Eds.): Numerical Methods for Limit and Shakedown Analysis. Deterministic and Probabilistic Approach. NIC Series Vol. 15, John von Neumann Institute for Computing, Jülich (2003) pp.217-268. www.fz-juelich.de/nic-series/volume15/nic-series-band15.pdf
  12. Duc Khoi Vu, M. Staat: An Algorithm for Shakedown Analysis for Materials with Temperature Dependent Yield Stress. PAMM - Proceedings in Applied Mathematics and Mechanics, 4 (1), (2004) 231-233. dx. doi.org/10.1002/pamm.200410097