@article{StaatHeitzer2002, author = {Staat, Manfred and Heitzer, M.}, title = {Limit and Shakedown Analysis with Uncertain Data}, series = {Stochastic optimization techniques : numerical methods and technical applications / Marti, K. [ed]}, journal = {Stochastic optimization techniques : numerical methods and technical applications / Marti, K. [ed]}, publisher = {Springer}, address = {Heidelberg}, isbn = {3-540-42889-5}, pages = {241 -- 254}, year = {2002}, language = {en} } @article{StaatHeitzer1997, author = {Staat, Manfred and Heitzer, M.}, title = {Limit and Shakedown Analysis Using a General Purpose Finite Element Code}, series = {Proceedings of NAFEMS World Congress '97 on Design, Simulation \& Optimisation : reliability \& applicability of computational methods ; Stuttgart, Germany, 9 - 11 April 1997}, journal = {Proceedings of NAFEMS World Congress '97 on Design, Simulation \& Optimisation : reliability \& applicability of computational methods ; Stuttgart, Germany, 9 - 11 April 1997}, publisher = {NAFEMS}, address = {Glasgow}, isbn = {1-87437-620-4}, pages = {522 -- 533}, year = {1997}, language = {en} } @inproceedings{Staat2012, author = {Staat, Manfred}, title = {Limit and shakedown analysis under uncertainty}, series = {Proceedings International Conference on Advances in Computational Mechanics (ACOME)}, booktitle = {Proceedings International Conference on Advances in Computational Mechanics (ACOME)}, pages = {837 -- 861}, year = {2012}, language = {de} } @article{Staat2013, author = {Staat, Manfred}, title = {Limit and shakedown analysis under uncertainty}, series = {International journal of computational methods : IJCM}, journal = {International journal of computational methods : IJCM}, publisher = {World Scientific Publishing}, address = {Singapore}, issn = {0219-8762}, pages = {Publ. online}, year = {2013}, language = {en} } @article{Staat2012, author = {Staat, Manfred}, title = {Limit and shakedown analysis under uncertainty}, series = {Tap chi Khoa hoc \& ung dung - Dai hoc Ton Duc Thang}, volume = {19}, journal = {Tap chi Khoa hoc \& ung dung - Dai hoc Ton Duc Thang}, pages = {45 -- 47}, year = {2012}, language = {en} } @inproceedings{TranTrinhDaoetal.2022, author = {Tran, Ngoc Trinh and Trinh, Tu Luc and Dao, Ngoc Tien and Giap, Van Tan and Truong, Manh Khuyen and Dinh, Thuy Ha and Staat, Manfred}, title = {Limit and shakedown analysis of structures under random strength}, series = {Proceedings of (NACOME2022) The 11th National Conference on Mechanics, Vol. 1. Solid Mechanics, Rock Mechanics, Artificial Intelligence, Teaching and Training, Hanoi, December 2-3, 2022}, booktitle = {Proceedings of (NACOME2022) The 11th National Conference on Mechanics, Vol. 1. Solid Mechanics, Rock Mechanics, Artificial Intelligence, Teaching and Training, Hanoi, December 2-3, 2022}, publisher = {Nha xuat ban Khoa hoc tu nhien va Cong nghe (Verlag Naturwissenschaft und Technik)}, address = {Hanoi}, isbn = {978-604-357-084-7}, pages = {510 -- 518}, year = {2022}, abstract = {Direct methods comprising limit and shakedown analysis is a branch of computational mechanics. It plays a significant role in mechanical and civil engineering design. The concept of direct method aims to determinate the ultimate load bearing capacity of structures beyond the elastic range. For practical problems, the direct methods lead to nonlinear convex optimization problems with a large number of variables and onstraints. If strength and loading are random quantities, the problem of shakedown analysis is considered as stochastic programming. This paper presents a method so called chance constrained programming, an effective method of stochastic programming, to solve shakedown analysis problem under random condition of strength. In this our investigation, the loading is deterministic, the strength is distributed as normal or lognormal variables.}, language = {en} } @article{StaatHeitzer1997, author = {Staat, Manfred and Heitzer, M.}, title = {Limit and Shakedown Analysis for Plastic Safety of Complex Structures}, series = {Transactions of the 14th International Conference on Structural Dynamics in Reactor Technology (SMiRT-14) / Livolant, M. [ed]}, journal = {Transactions of the 14th International Conference on Structural Dynamics in Reactor Technology (SMiRT-14) / Livolant, M. [ed]}, address = {Lyon}, pages = {33 -- 40}, year = {1997}, language = {en} } @inproceedings{StaatHeitzer1997, author = {Staat, Manfred and Heitzer, Michael}, title = {Limit and shakedown analysis for plastic design}, year = {1997}, abstract = {Limit and shakedown theorems are exact theories of classical plasticity for the direct computation of safety factors or of the load carrying capacity under constant and varying loads. Simple versions of limit and shakedown analysis are the basis of all design codes for pressure vessels and pipings. Using Finite Element Methods more realistic modeling can be used for a more rational design. The methods can be extended to yield optimum plastic design. In this paper we present a first implementation in FE of limit and shakedown analyses for perfectly plastic material. Limit and shakedown analyses are done of a pipe-junction and a interaction diagram is calculated. The results are in good correspondence with the analytic solution we give in the appendix.}, subject = {Einspielen }, language = {en} } @article{StaatVu2007, author = {Staat, Manfred and Vu, Duc-Khoi}, title = {Limit analysis of flaws in pressurized pipes and cylindrical vessels. Part I: Axial defects}, series = {Engineering Fracture Mechanics. 74 (2007), H. 3}, journal = {Engineering Fracture Mechanics. 74 (2007), H. 3}, isbn = {0013-7944}, pages = {431 -- 450}, year = {2007}, language = {en} } @article{StaatVu2012, author = {Staat, Manfred and Vu, Duc Khoi}, title = {Limit analysis of flaws in pressurized pipes and cylindrical vessels Part II: Circumferential defects}, series = {Engineering Fracture Mechanics ; 97(2013), H. 1}, volume = {97}, journal = {Engineering Fracture Mechanics ; 97(2013), H. 1}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0013-7944}, doi = {10.1016/j.engfracmech.2012.05.017}, pages = {314 -- 333}, year = {2012}, abstract = {Upper and lower bound theorems of limit analyses have been presented in part I of the paper. Part II starts with the finite element discretization of these theorems and demonstrates how both can be combined in a primal-dual optimization problem. This recently proposed numerical method is used to guide the development of a new class of closed-form limit loads for circumferential defects, which show that only large defects contribute to plastic collapse with a rapid loss of strength with increasing crack sizes. The formulae are compared with primal-dual FEM limit analyses and with burst tests. Even closer predictions are obtained with iterative limit load solutions for the von Mises yield function and for the Tresca yield function. Pressure loading of the faces of interior cracks in thick pipes reduces the collapse load of circumferential defects more than for axial flaws. Axial defects have been treated in part I of the paper.}, language = {en} } @book{StaatHeitzerYanetal.2000, author = {Staat, Manfred and Heitzer, M. and Yan, Ai-Min and Khoi, Vu Duc and Nguyen, Dang Hung and Valdoire, F. and Lahousse, A.}, title = {Limit Analysis of Defects}, publisher = {Forschungszentrum J{\"u}lich}, address = {J{\"u}lich}, issn = {0944-2952}, pages = {89 S.}, year = {2000}, language = {en} } @article{BhattaraiMayStaatetal.2022, author = {Bhattarai, Aroj and May, Charlotte Anabell and Staat, Manfred and Kowalczyk, Wojciech and Tran, Thanh Ngoc}, title = {Layer-specific damage modeling of porcine large intestine under biaxial tension}, series = {Bioengineering}, volume = {9}, journal = {Bioengineering}, number = {10, Early Access}, publisher = {MDPI}, address = {Basel}, issn = {2306-5354}, doi = {10.3390/bioengineering9100528}, pages = {1 -- 17}, year = {2022}, abstract = {The mechanical behavior of the large intestine beyond the ultimate stress has never been investigated. Stretching beyond the ultimate stress may drastically impair the tissue microstructure, which consequently weakens its healthy state functions of absorption, temporary storage, and transportation for defecation. Due to closely similar microstructure and function with humans, biaxial tensile experiments on the porcine large intestine have been performed in this study. In this paper, we report hyperelastic characterization of the large intestine based on experiments in 102 specimens. We also report the theoretical analysis of the experimental results, including an exponential damage evolution function. The fracture energies and the threshold stresses are set as damage material parameters for the longitudinal muscular, the circumferential muscular and the submucosal collagenous layers. A biaxial tensile simulation of a linear brick element has been performed to validate the applicability of the estimated material parameters. The model successfully simulates the biomechanical response of the large intestine under physiological and non-physiological loads.}, language = {en} } @article{MeyerGaalenLeschingeretal.2019, author = {Meyer, Carolin and Gaalen, Kerstin van and Leschinger, Tim and Scheyerer, Max J. and Neiss, Wolfram F. and Staat, Manfred and M{\"u}ller, Lars P. and Wegmann, Kilian}, title = {Kyphoplasty of Osteoporotic Fractured Vertebrae: A Finite Element Analysis about Two Types of Cement}, series = {BioMed Research International}, journal = {BioMed Research International}, doi = {10.1155/2019/9232813}, pages = {Article ID 9232813}, year = {2019}, language = {en} } @inproceedings{StaatSzelinskiHeitzer2001, author = {Staat, Manfred and Szelinski, E. and Heitzer, Michael}, title = {Kollapsanalyse von l{\"a}ngsfehlerbehafteten Rohren und Beh{\"a}ltern}, year = {2001}, abstract = {Es werden verbesserte Kollapsanalysen von dickwandigen, mit axialen Oberfl{\"a}chenfehlern behafteten Rohren und Beh{\"a}ltern vorgeschlagen.}, subject = {Druckbeh{\"a}lter}, language = {de} } @article{LeschingerBeschAydinetal.2019, author = {Leschinger, Tim and Besch, Katharina and Aydin, Cansu and Staat, Manfred and Scaal, Martin and M{\"u}ller, Lars Peter and Wegmann, Kilian}, title = {Irreparable rotator cuff tears: a biomechanical comparison of superior capsuloligamentous complex reconstruction techniques and an interposition graft technique}, series = {The Orthopaedic Journal of Sports Medicine}, volume = {7}, journal = {The Orthopaedic Journal of Sports Medicine}, number = {8}, doi = {10.1177/2325967119864590}, pages = {1 -- 5}, year = {2019}, language = {en} } @article{AndingTabazaStaatetal.2013, author = {Anding, Ralf and Tabaza, Ruth and Staat, Manfred and Trenz, Eva and Lohmann, Philipp and Klinge, Uwe and Kirschner-Hermanns, Ruth}, title = {Introducing a method of in vitro testing of different anchoring systems used for female incontinence and prolapse surgery}, series = {BioMed research international}, volume = {Vol. 2013}, journal = {BioMed research international}, issn = {1110-7251 (E-Journal); 2314-6141 (E-Journal); 1110-7243 (Print); 2314-6133 (Print)}, pages = {Article ID 401417}, year = {2013}, language = {en} } @article{HacklNacovKammerlohretal.2021, author = {Hackl, Michael and Nacov, Julia and Kammerlohr, Sandra and Staat, Manfred and Buess, Eduard and Leschinger, Tim and M{\"u}ller, Lars P. and Wegmann, Kilian}, title = {Intratendinous Strain Variations of the Supraspinatus Tendon Depending on Repair Technique: A Biomechanical Analysis Regarding the Cause of Medial Cuff Failure}, series = {The American Journal of Sports Medicine}, volume = {49}, journal = {The American Journal of Sports Medicine}, number = {7}, publisher = {Sage}, address = {London}, issn = {1552-3365}, doi = {10.1177/03635465211006138}, pages = {1847 -- 1853}, year = {2021}, language = {en} } @article{DuongNguyenTranetal.2015, author = {Duong, Minh Tuan and Nguyen, Nhu Huynh and Tran, Thanh Ngoc and Tolba, R. H. and Staat, Manfred}, title = {Influence of refrigerated storage on tensile mechanical properties of porcine liver and spleen}, series = {International biomechanics}, volume = {Vol. 2}, journal = {International biomechanics}, number = {Iss. 1}, publisher = {Taylor \& Francis}, address = {London}, issn = {2333-5432}, doi = {10.1080/23335432.2015.1049295}, pages = {79 -- 88}, year = {2015}, language = {en} } @article{NguyenDuongTranetal.2012, author = {Nguyen, Nhu Huynh and Duong, Minh Tuan and Tran, Thanh Ngoc and Pham, Phu Tinh and Grottke, O. and Tolba, R. and Staat, Manfred}, title = {Influence of a freeze-thaw cycle on the stress-stretch curves of tissues of porcine abdominal organs}, series = {Journal of Biomechanics}, volume = {45}, journal = {Journal of Biomechanics}, number = {14}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-2380}, doi = {10.1016/j.jbiomech.2012.07.008}, pages = {2382 -- 2386}, year = {2012}, abstract = {The paper investigates both fresh porcine spleen and liver and the possible decomposition of these organs under a freeze-thaw cycle. The effect of tissue preservation condition is an important factor which should be taken into account for protracted biomechanical tests. In this work, tension tests were conducted for a large number of tissue specimens from twenty pigs divided into two groups of 10. Concretely, the first group was tested in fresh state; the other one was tested after a freeze-thaw cycle which simulates the conservation conditions before biomechanical experiments. A modified Fung model for isotropic behavior was adopted for the curve fitting of each kind of tissues. Experimental results show strong effects of the realistic freeze-thaw cycle on the capsule of elastin-rich spleen but negligible effects on the liver which virtually contains no elastin. This different behavior could be explained by the autolysis of elastin by elastolytic enzymes during the warmer period after thawing. Realistic biomechanical properties of elastin-rich organs can only be expected if really fresh tissue is tested. The observations are supported by tests of intestines.}, language = {en} } @inproceedings{NixFrotscherStaat2012, author = {Nix, Yvonne and Frotscher, Ralf and Staat, Manfred}, title = {Implementation of the edge-based smoothed extended finite element method}, series = {Proceedings 6th European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2012) Vienna, Austria, September 10-14, 2012}, booktitle = {Proceedings 6th European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2012) Vienna, Austria, September 10-14, 2012}, editor = {Eberhardsteiner, J.}, year = {2012}, language = {en} }