@article{VuStaat2004, author = {Vu, Duc-Khoi and Staat, Manfred}, title = {An algorithm for shakedown analysis of structure with temperature dependent yield stress}, year = {2004}, abstract = {This work is an attempt to answer the question: How to use convex programming in shakedown analysis of structures made of materials with temperature-dependent properties. Based on recently established shakedown theorems and formulations, a dual relationship between upper and lower bounds of the shakedown limit load is found, an algorithmfor shakedown analysis is proposed. While the original problem is neither convex nor concave, the algorithm presented here has the advantage of employing convex programming tools.}, subject = {Einspielen }, language = {en} } @article{TranStaat2013, author = {Tran, Thanh Ngoc and Staat, Manfred}, title = {An Edge-Based Smoothed Finite Element Method for Primal-Dual Shakedown Analysis of Structures Under Uncertainties}, series = {Limit State of Materials and Structures : Direct Methods 2. Saxc{\´e}, G{\´e}ry de (Hrsg.)}, journal = {Limit State of Materials and Structures : Direct Methods 2. Saxc{\´e}, G{\´e}ry de (Hrsg.)}, publisher = {Springer}, address = {Dordrecht}, isbn = {978-94-007-5424-9}, pages = {89 -- 102}, year = {2013}, language = {en} } @article{ColomboDriraFrotscheretal.2022, author = {Colombo, Daniele and Drira, Slah and Frotscher, Ralf and Staat, Manfred}, title = {An element-based formulation for ES-FEM and FS-FEM models for implementation in standard solid mechanics finite element codes for 2D and 3D static analysis}, series = {International Journal for Numerical Methods in Engineering}, volume = {124}, journal = {International Journal for Numerical Methods in Engineering}, number = {2}, publisher = {Wiley}, address = {Chichester}, issn = {1097-0207}, doi = {10.1002/nme.7126}, pages = {402 -- 433}, year = {2022}, abstract = {Edge-based and face-based smoothed finite element methods (ES-FEM and FS-FEM, respectively) are modified versions of the finite element method allowing to achieve more accurate results and to reduce sensitivity to mesh distortion, at least for linear elements. These properties make the two methods very attractive. However, their implementation in a standard finite element code is nontrivial because it requires heavy and extensive modifications to the code architecture. In this article, we present an element-based formulation of ES-FEM and FS-FEM methods allowing to implement the two methods in a standard finite element code with no modifications to its architecture. Moreover, the element-based formulation permits to easily manage any type of element, especially in 3D models where, to the best of the authors' knowledge, only tetrahedral elements are used in FS-FEM applications found in the literature. Shape functions for non-simplex 3D elements are proposed in order to apply FS-FEM to any standard finite element.}, language = {en} } @article{StaatKuehnHaugeretal.2004, author = {Staat, Manfred and K{\"u}hn, R. and Hauger, W. and Sponagel, Stefan}, title = {An Interpretation of Wolff's Law}, series = {Biomedizinische Technik. 49 (2004)}, journal = {Biomedizinische Technik. 49 (2004)}, isbn = {0932-4666}, pages = {1020 -- 1021}, year = {2004}, language = {de} } @article{AbelKahmannMellonetal.2020, author = {Abel, Alexander and Kahmann, Stephanie Lucina and Mellon, Stephen and Staat, Manfred and Jung, Alexander}, title = {An open-source tool for the validation of finite element models using three-dimensional full-field measurements}, series = {Medical Engineering \& Physics}, volume = {77}, journal = {Medical Engineering \& Physics}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1350-4533}, doi = {10.1016/j.medengphy.2019.10.015}, pages = {125 -- 129}, year = {2020}, abstract = {Three-dimensional (3D) full-field measurements provide a comprehensive and accurate validation of finite element (FE) models. For the validation, the result of the model and measurements are compared based on two respective point-sets and this requires the point-sets to be registered in one coordinate system. Point-set registration is a non-convex optimization problem that has widely been solved by the ordinary iterative closest point algorithm. However, this approach necessitates a good initialization without which it easily returns a local optimum, i.e. an erroneous registration. The globally optimal iterative closest point (Go-ICP) algorithm has overcome this drawback and forms the basis for the presented open-source tool that can be used for the validation of FE models using 3D full-field measurements. The capability of the tool is demonstrated using an application example from the field of biomechanics. Methodological problems that arise in real-world data and the respective implemented solution approaches are discussed.}, language = {en} } @article{PhamStaat2013, author = {Pham, Phu Tinh and Staat, Manfred}, title = {An Upper Bound Algorithm for Limit and Shakedown Analysis of Bounded Linearly Kinematic Hardening Structures}, series = {Limit State of Materials and Structures : Direct Methods 2. Saxc{\´e}, G{\´e}ry de (Hrsg.)}, journal = {Limit State of Materials and Structures : Direct Methods 2. Saxc{\´e}, G{\´e}ry de (Hrsg.)}, publisher = {Springer}, address = {Dordrecht}, isbn = {978-94-007-5424-9}, pages = {71 -- 87}, year = {2013}, language = {en} } @article{LeversStaatLaack2011, author = {Levers, A. and Staat, Manfred and Laack, Walter van}, title = {Analyse der Langzeitwirkung der MBST® KernspinResonanzTherapie bei Gonarthrose}, year = {2011}, abstract = {Originalausgabe: Orthop{\"a}dische Praxis Jg. 47. 2011 H. 11; S. 536-543. Mit freundlicher Genehmigung des Verlags Zusammenfassung: Auf der Basis von Patientenabfragen mittels Fragebogen zum Schmerzempfinden und zur Einschr{\"a}nkung bei Aktivit{\"a}ten des allt{\"a}glichen Lebens wird die Langzeitwirkung der MBST® KernspinResonanz-Therapie bei Gonarthrose untersucht. An der Studie nahmen 39 Patienten teil, bei denen die Therapie bis zu vier Jahre zur{\"u}ckliegt. Neben einer Gesamtbetrachtung wird der Erfolg auch in Abh{\"a}ngigkeit von Alter, Geschlecht und sportlicher Aktivit{\"a}t analysiert. Insgesamt weist die Studie auf eine anhaltende Verbesserung des Gesundheitszustands mit zum Teil deutlicher Schmerzlinderung auch noch nach vier Jahren hin, jedoch mit einer leichten Schmerzzunahme gegen Ende des Untersuchungszeitraums von vier Jahren. Eine tendenziell positivere Wirkung bei Frauen, {\"a}lteren Menschen oder auch sportlich nicht-aktiven Patienten l{\"a}sst auf eine m{\"o}gliche Beeinflussung des Erfolgs der Therapie durch ({\"U}ber-)Belastung im Alltag schließen. Ein zus{\"a}tzlich positiver Effekt der Therapie auf die Knochendichte ist ebenfalls denkbar, dies bleibt jedoch offen.}, subject = {Kniegelenkarthrose}, language = {de} } @article{VuStaatTran2007, author = {Vu, Duc Khoi and Staat, Manfred and Tran, Ich Thinh}, title = {Analysis of pressure equipment by application of the primal-dual theory of shakedown}, series = {Communications in Numerical Methods in Engineering. 23 (2007), H. 3}, journal = {Communications in Numerical Methods in Engineering. 23 (2007), H. 3}, isbn = {1069-8299}, pages = {213 -- 225}, year = {2007}, language = {en} } @article{LeversStaatLaack2016, author = {Levers, A. and Staat, Manfred and Laack, Walter van}, title = {Analysis of the long-term effect of the MBST® nuclear magnetic resonance therapy on gonarthrosis}, series = {Orthopedic Practice}, volume = {47}, journal = {Orthopedic Practice}, number = {11}, pages = {521 -- 528}, year = {2016}, language = {en} } @article{StaatBallmann1985, author = {Staat, Manfred and Ballmann, J.}, title = {Anisotrope Ausbreitung und Fokussierung von Beschleunigungswellen in vorgespannten nichtlinearelastischen Scheiben}, series = {Wellenfokussierung, Kolloquium des SFB 27, RWTH Aachen}, journal = {Wellenfokussierung, Kolloquium des SFB 27, RWTH Aachen}, address = {Aachen}, pages = {140 -- 158}, year = {1985}, language = {de} }