Institute of Mechanics and Fluid Dynamics · Fracture mechanical stress analysis and safety...
Transcript of Institute of Mechanics and Fluid Dynamics · Fracture mechanical stress analysis and safety...
Institute of MechanicsInstitute of Mechanicsand Fluid Dynamicsand Fluid Dynamics
Research GroupResearch GroupSolid MechanicsSolid Mechanics
Prof.Dr.rer.nat.habil. Meinhard Kuna
Main research topics
Offered engineering service
Fracture mechanical stress analysis and safety assess- ment of structural compo- nents
Fracture mechanical stress analysis of compo- nents (static, dynamic, cyclic, stochastic)
Assessment of strength, reliability and life time
Materials testing with small specimens and para- meter identification
Provision of numerical techniques (FEM, BEM) and software for fracture and damage mechanics
Development and implementation of progressive user-specific material models
Damage mechanics simulation of material failure (metal forming, crash, …)
Further education seminars on„Finite element methods in fracture mechanics“
Development of computa- tional methods in fracture and solid mechanics
Smart mechanical systems
Mechanics of materials and damage mechanics
Technical equipment
Experimental technique
Universal materials testing machines AGS: max. force 10 kN and 250 kN
Micro testing machine SHIMADZU-Micro-Servo-Pulser (max. 100 N, 0 – 60 Hz)
Optical three dimensional deformation measurement system with object grating method ARAMIS
Optical stress measurement systems VISHAY (light polarization in transmission and reflexion)
Computational technique
Compute server LINUX-Cluster with 10 nodes (each 16 CPU AMD Barcelona, 64 GByte RAM, Infiniband, 300 GByte disk)
File Server 6 TByte, RAID, Backup system, USV
Computer Pool FEM/CAD for students (10 High per- formance PC 2 CPU AMD Opteron, LINUX)
FEM: ABAQUS, ANSYS, PATRAN
own developed FEM, BEM and DEM codes
MATLAB, Mathematica, CAD-systems a. o.
Software
Fracture mechanical stress analysis and safety assessment of components
Fundamental and applied research in fracture mechanics and classical theory of strength to evaluate the safety, reliability and life time of engineering constructions from nuclear power plants, gas pipelines, wind turbines, comminution machines, automotives and microelec- tronics. Development of failure criteria and assessment procedures.
Development of fracture mechanics assessment system for high-pressure gas pipelines
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Safety evaluation of girth welds in the pipeline system of former east Germany
Development of a fracture mechanics concept based on Failure-Assessment-Diagram FAD
Interactive software tool, supporting the test engineer during non-destructive inspections of welds to evaluate detected defects in dependence on pressure, additional axial loads and eigenstresses.
Fracture mechanical strength analysis of railway wheels from ductile cast iron ADI
Verification of safety against static fracture and fatigue crack growth during design phase
Deduction of tolerable crack size in connection with in-service inspection procedures
Simulation of drop tests of nuclear shipping casks
Safety design requires consideration of dynamic impact loading
Development of computational tools to determine dynamic fracture mechanics loading parameters
FEM-simulation of drop tests assuming hypothetical cracks in the casks
Smart mechanical structures
In high-tech-branches as aeronautics, automotives, mechatronics and micro system technology one aims a smart, self-adapting behaviour of engineering construc- tions by combining structural, sensoric, actoric as well as controlling components. These recent developments need investigations by simulation of coupled mechanical, thermal and electromagnetical behaviour of the smart structures and the new smart composite materials.
Electromechanical modelling of composites with integrated piezo ceramics
Continuum mechanical analysis of internal electro- mechanical loading in smart piezoelectric fibre or layer composites to optimize the materials design
Development of analytical and numerical models to eva- luate the elec-tromechanical strength of in- terface cracks
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Fracture mechanics of ferroelectric ceramics
Calculations to analyse and interpret fracture mechanical experiments with piezoelectrica
Simulation of micromechanical processes at the crack tip, e. g. numerical and semi-analytical models of ferroelectric domain switching and its effect on frac- ture toughness
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Development of numerical methods to compute intensity factors and energy release rates
Theoretical modelling and numerical simulation of micro structural processes during deformation and failure in techniqual materials using methods of constitutive thermodynamics theory, damage mechanics and homogenization. Application to optimization and evaluation of material properties during their production and under complex in-service conditions. Particularly, the brittle, ductile and the nil-ductile transition behaviour of failure in metals, ceramics and semi-conductors is studied.
Materials modelling and damage mechanics
Identification of elastoplastic and damage parameters
To apply plastic and damage mechanics material laws, determination of relevant parameters is needed (e. g. Gurson law)
Measurement of displacement fields on notched tensile specimens by means of object grating method
Identification of material parameters from measured inhomogeneous displacement fields and FEM- simulation using non-linear optimization algorithms
Determination of ductile deformation and failure properties by miniaturized Small-Punch-Test
Surveillance of the local material state in structural components by minimal invasive removal of repre- sentative miniature specimens
Mechanical loading of the specimens in a deep drawing test (SPT) until failure
Determination of true yield curve and damage parame- ters (Gurson, Beremin) from test records by means of numerical simulation and neural networks
Solder joints in micro electronics
Challenge of new lead free solder alloys in surface mounting technology
Prediction of life time and reliability of solder joints under thermomechanical fatigue
Development of viscoplastic ma- terial model for temperature de- pendent creep, cyclic plasticity and damage (by void growth)
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Granular matter
Numerical simulation of brittle granular materials under mechanical loading
Application of finite ele- ment (FEM) and discrete element methods (DEM)
Investigation of force dis- tribution and brittle frac-ture Weibull parameters as function of statistical arrangement and proper-ties of particles
Development of computational methods in solid and fracture mechanics
Enhancements of numerical methods in solid mechanics (finite element method FEM, boundary element method BEM) for the analysis of crack problems, fo r implementation of damage laws and for treatment of coupled field problems.
Finite element simulation of crack growth
Simulation of crack growth requires adaptive remeshing of finite elements
Development of effective numerical algorithms for auto- matic, error-con- trolled mesh adap- tation
Supply of compu- tational tools for crack growth under mixed-mode-loading
Contact
TU Bergakademie FreibergInstitute of Mechanics and Fluid DynamicsLampadiusstr. 409596 Freiberg
Secretary: +49 (0)3731 39 2465
Prof. Dr.rer.nat.habil. M. Kuna: +49 (0)3731 39 2092
Telefax: +49 (0)3731 39 3455
Internet: http://imfd.tu-freiberg.de
Email: [email protected]
Approach