@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}
}
@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{PhamStaat2014,
  author    = {Pham, Phu Tinh and Staat, Manfred},
  title     = {FEM-based shakedown analysis of hardening structures},
  series = {Asia Pacific journal on computational engineering},
  journal   = {Asia Pacific journal on computational engineering},
  number    = {1},
  publisher = {SpringerOpen},
  address   = {Berlin},
  issn      = {2196-1166 (E-Journal)},
  doi       = {10.1186/2196-1166-1-4},
  pages     = {Article No. 4},
  year      = {2014},
  abstract  = {This paper develops a new finite element method (FEM)-based upper bound algorithm for limit and shakedown analysis of hardening structures by a direct plasticity method. The hardening model is a simple two-surface model of plasticity with a fixed bounding surface. The initial yield surface can translate inside the bounding surface, and it is bounded by one of the two equivalent conditions: (1) it always stays inside the bounding surface or (2) its centre cannot move outside the back-stress surface. The algorithm gives an effective tool to analyze the problems with a very high number of degree of freedom. Our numerical results are very close to the analytical solutions and numerical solutions in literature.},
  language  = {en}
}
@article{PhamVuTranetal.2010,
  author    = {Pham, Phu Tinh and Vu, Khoi Duc and Tran, Thanh Ngoc and Staat, Manfred},
  title     = {A primal-dual algorithm for shakedown analysis of elastic-plastic bounded linearly kinematic hardening bodies},
  pages     = {1 -- 7},
  year      = {2010},
  language  = {en}
}
@article{TranPhamVuetal.2009,
  author    = {Tran, Thanh Ngoc and Pham, Phu Tinh and Vu, D. K. and Staat, Manfred},
  title     = {Reliability Analysis of Inelastic Shell Structures Under Variable Loads},
  series = {Limit States of Materials and Structures : Direct Methods / Hrsg. Dieter Weichert; Hrsg. Alan Ponter},
  journal   = {Limit States of Materials and Structures : Direct Methods / Hrsg. Dieter Weichert; Hrsg. Alan Ponter},
  publisher = {Springer Netherland},
  address   = {Berlin},
  isbn      = {978-1-4020-9633-4},
  pages     = {135 -- 156},
  year      = {2009},
  language  = {en}
}