Numerische Optimierung von bioinspirierten keramischen Werkstoffsystemen

• Applicant: Professor Dr. Siegfried Schmauder
• Subject Area: Synthesis and Properties of Functional Materials ; Biomaterials ; Materials in Sintering Processes and Generative Manufacturing Processes
• Term: from 2009 to 2013
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 112803565

• Final Report Year: 2014

Final Report Abstract

In this project we developed numerical and analytical models to describe the material properties of different bio-inspired nanocomposites and its components. By comparison of existing material tests with our finite element and analytical models, we could derive material properties of the constituents of the Titandioxide (Titania, TiO2)/Polyelectrolyte (PE) based nanocomposite. We showed that the material properties of the constituents alone cannot describe the material behaviour of the nanocomposite. We gave a possible explanation for the high Young’s modulus in the range of 10 nm thick layers of PE in the nanocomposite. Mineral bridges, which are created during the manufacturing process of the nanocomposite, reinforce the material. But this structural feature alone is not sufficient to explain the high stiffness of the material. The mineral bridges undergo most likely a phase change to a crystalline structure (rutile). This reinforces the mineral bridges (the Young’s modulus raises by a factor of 8) and thus the composite. By in cooperating these features into the numerical model, the simulation and the experiments showed comparable results. In future works, this information should be verified and then used to establish a material with further increased hardness, but also with the highest possible fracture toughness. The second part of the project covered a combination of Molecular Dynamic (MD) and Finite Element Method (FEM) analysis in the frame of a multiscale simulation. The project partner from the ITB calculated the binding affinities of a peptide and three conformations of it with high binding affinities to a Zincoxide (ZnO) surface. The results of the MD simulation were analysed and transformed for the use in FEM simulations of a tensile test and a three point bending test. The coupling of MD simulations with FEM simulations via cohesive elements and the here presented traction separation law showed a good consistency. The comparison between the three conformations exposed that the results are in the same range but conformation 2 is the one with the highest binding capabilities in the FEM simulations and shows a maximum force resistance with a YM of 73.5 GPa. Conformation 1 shows the least force resistance in these simulations, and conformation 3, which had the maximum binding capabilities in the MD simulations, needs less force until the crack grows, but shows the highest value of crack opening displacements (COD) (about 0.7 nm) at the starting point of crack growth. The results of the COD simulation showed that the influence of the different conformations on the crack opening is high and also depends on the Young’s modulus of the protein. The results confirm that coupling of MD simulations and FEM simulation via cohesive elements to find a peptide with good binding affinities to ZnO shows reasonable results and can be easily transferred to other ceramic composite systems in future works. Combined with the structural features analysed in the first part of the project the development of very stiff but ductile nanomaterials based on peptides and ceramics should be possible.

Publications

• Numerical optimization of bioinspired ceramics material systems. International one-day Workshop “Prospects of Bionics for functional Materials Science and Engineering“, 22 September, 2010, Leoben, Austria
  Galina Lasko, Žaklina Burghard, Siegfried Schmauder, Ulrich Weber and Axel Krebs
  
• Numerical optimization of bioinspired ceramics material systems. International symposium “Molecular Bionics-From biomineralization to functional materials“ 3-6 October 2010, Schloss Ringberg, Rottach-Egern, Germany
  Galina Lasko, Siegfried Schmauder, Ulrich Weber, Žaklina Burghard and Andreas Reuschel
  
• FEM-Simulation der mechanischen Eigenschaften bionisch inspirierter TiO2/PE Nano-Verbundwerkstoffe at the Jahrestagung der Deutschen Gesellschaft für Biomaterialien 2011, 10-12 November 2011, Gießen, Germany. Biomaterialien 12 (2011), 110
  Galina Lasko
  
• Simulation der mechanischen Eigenschaften von bio-inspirierten TiO2/PE Nanoverbundmaterial. Tagungsband zum 6. Bionik-Kongress "Patente aus der Natur", Oktober 26-27, Bremen, Germany, (2012), ISBN 978-3-00-040885-4, Gesellschaft für Technische Biologie und Bionik
  Galina Lasko, Žaklina Burghard, Joachim Bill, Immanuel Schäfer, Ulrich Weber and Siegfried Schmauder
  
• Derivation of Stress-Strain Behavior of Bio-Inspired Layered TiO 2 /PE-Nanocomposite by Inverse Modeling based on FE-Simulations of Nanoindentation Test, Molecular & Cellular Biomechanics special issue (2013), 10:27–42
  Galina Lasko, Žaklina Burghard, Immanuel Schäfer, Siegfried Schmauder, Ulrich Weber and Dieter Galler
  
• Simulation of Mechanical Properties of Bio-Inspired TiO2/PE Nanocomposites, Advanced Engineering Materials, (2013), 15:908–920
  Galina Lasko, Žaklina Burghard, Joachim Bill, Immanuel Schäfer, Siegfried Schmauder and Ulrich Weber
  
• Peptide–zinc oxide interaction: Finite element simulation using cohesive zone models based on molecular dynamics simulation, Computational Materials Science, Volume 95, December 2014, Pages 320-327
  Immanuel Schäfer, Galina Lasko, Tuan Anh Do, Jürgen Pleiss, Ulrich Weber and Siegfried Schmauder