Master Thesis Projects - in ModSimCompMech: Difference between revisions

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=Announced projects=
=Announced projects=


==Merge/split in rigid multibody simulation==
==Algorithms and software for co-simulation==
Adaptive simplification of rigid multibody systems by merging bodies into agglomerate superbodies can accelerate large-scale simulation by many orders in magnitude. The actions should preserves physical invariants, minimizes computational time, produce consistent pressure force distributions and allow for impulse propagation. Application to vehicle or robot simulations with large piles of contacting bodies.
Co-simulation is when software packages are coupled together as black boxes and this poses a number of stability problems.  Algorithms and numerical methods are being investigated at UMIT in conjunction with a large project involving Scania and Volvo Cars, but there is a need to perform large scale testing and analysis of these. Of interest here is a study of adaptive time stepping if possible at all.


==Quantitative analysis of frictional contact models and solvers==
==Simulation of mining vehicles and granular crash berms==
Implement different formulations of dry friction for rigid bodies - some old and some new; performance analysis including: testing pipeline, design of statistical measures, scientific visualization of results.
The aim of the project is to find an optimal geometry/material for the berm and to determine their energy absorption capacity. This requires modeling and simulation of a haul truck running into a crash berm. The specific aims of the thesis can be summarized as follows.
* model calibration of granular material and haul truck based on full-scale experiments
* exploration of the crash berm design space using rigid multibody simulation
* identification of optimal parameters and of critical scenarios


==Parallel numerical solutions of sparse linear systems==
==Nonsmooth, analytical models for electric machinery for multidomain simulations==
* hierarchical data formats for sparse matrices
The variational principle of classical mechanics can be used to simulate multidomain physical systems, including multibody dynamics, electronics, hydraulics, and electric machinery.  This can also be combined with methods for nonsmooth mechanics, i.e., systems subject to discontinuities such as impacts, contacts, switching modes, etc.
* factorization update and downdate
* load balancing
* quantitative comparisons to existing libraries


==Geometric contact reduction for 3D objects==
We have previously developed methods for rigid multibody with frictional contacts, non-smooth hydraulics and non-smooth electronics, all of which turned out
It is possible to identify contact points that are redundant to the dynamics contacting rigid body system simulations. Eliminating redundant contact can have dramatic effect on the computational performance. The project include: implementing existing models, development of new techniques (advanced), quantitative evaluation of contact set quality.
to be much faster than available software packages for the same level of accuracy.


==Multiphysics: coupling of fluid with rigid multibody dynamics on GPGPU==
Extending this to include electrical motors will allow for comprehensive simulation of robots for instance, but also electric cars and such.
* evaluation of solvers
* evaluation of models for boundary conditions
* management of shared memory between CPU and GPGPU


==Analytical system dynamics==
==Multibody dynamics modeling of bacterial biofilm==
Testing theoretical models and numerical simulations of coupled systems including: rigid multibodies, hydraulics (fluid power), electrical networks, heat transfer.


==Adaptive resolution in particle fluid simulation==
==Simple adaptive time step for low order stepping scheme==
Extension of existing constraint based particle fluids to adaptive level of detail. Alternatives to particle representation of coarse grained regions. Application to industrial systems or scientific studies of ocean freak waves.


==Real-time simulation models of ground-tire interaction and transmission lines==
==Jamming phenomena in flowing granular media==
New contact model for ground-tire interaction suitable for real-time simulation of constrained multibody systems. Constraint based modeling of transmission lines. Applications to new design of terrain vehicles.


==New contact and friction models==
==Benchmarking of frictional contact solvers==
Contact reduction (theory, implementation, analysis); evaluation of a number of existing contact models (implementation, analysis) of Anitescu/Potra, Anitescu/Hart, Kaufamn/Pai, pairwise models, Kane/Pandolfi; development of a new model including reduction, delocalization and aspirity (theory, implementation, analysis); splitting technique for friction LCP solver.


==Sparse parallel solvers with applications to QP==
==Graph partitioning and load balancing for sparse matrix solvers==
Sparse parallel factorization of LDL update and downdate with applications to quadratic programming (QP); block pivot methods for QPs (smoothing, splitting, application to frictional contacts, direct iterative hybrid solver); splitting techniques for frictional LCP solver; GPGPU techniques (sparse direct LDL solver, CG preconditioning, application to QP contact problems).


==Time-integration of non-smooth dynamical systems==
==Merging and splitting bodies dynamically==
Linear and nonlinear constraint stabilization, impacts and nonsmooth mechanics, geometric integration and invariants, stable integration of rotational degrees of frodeom, robotics O(N) solver for closed loop systems.


=Running projects=
==Simulating ships moving in shallow waters==
* Projected conjugate-gradient solver for contacting rigid bodies on GPGPU
 
* Parallel factorization of symmetric indefinite linear systems
==Added mass computations==
* Parallelization of conjugate gradient solver for mixed linear complementarity problem
 
==Stable joint kinematics using Euler angles==
 
==Modeling hydraulic components with non-smooth methods==
 
==Modeling tracked vehicles on soft terrain==
 
==Control of granular systems==


=Previous projects=
=Previous projects=
* Projected conjugate-gradient solver for contacting rigid bodies on GPGPU
* Parallel projected Gauss-Seidel solver for large-scale granular matter - Examining the physics of the parallel solver and development of a multigrid solver (Johan Sundberg)
* Parallel projected Gauss-Seidel solver for large-scale granular matter - Examining the physics of the parallel solver and development of a multigrid solver (Johan Sundberg)
* Discrete time variational mechanics of multidomain systems: Applications to coupled electronic, hydraulic, and multibody systems (Tomas Sjöström)
* Discrete time variational mechanics of multidomain systems: Applications to coupled electronic, hydraulic, and multibody systems (Tomas Sjöström)

Revision as of 14:59, 15 June 2015

The research group in Modeling and simulation of complex mechanical systems offer projects mainly in computational science and engineering. Your background could be applied mathematics, computer science, computational physics, control, mechanical engineering, robotics - but this is not exclusive. Please contact us with your interest and CV. Feel free also to propose thesis project by yourself.

Announced projects

Algorithms and software for co-simulation

Co-simulation is when software packages are coupled together as black boxes and this poses a number of stability problems. Algorithms and numerical methods are being investigated at UMIT in conjunction with a large project involving Scania and Volvo Cars, but there is a need to perform large scale testing and analysis of these. Of interest here is a study of adaptive time stepping if possible at all.

Simulation of mining vehicles and granular crash berms

The aim of the project is to find an optimal geometry/material for the berm and to determine their energy absorption capacity. This requires modeling and simulation of a haul truck running into a crash berm. The specific aims of the thesis can be summarized as follows.

  • model calibration of granular material and haul truck based on full-scale experiments
  • exploration of the crash berm design space using rigid multibody simulation
  • identification of optimal parameters and of critical scenarios

Nonsmooth, analytical models for electric machinery for multidomain simulations

The variational principle of classical mechanics can be used to simulate multidomain physical systems, including multibody dynamics, electronics, hydraulics, and electric machinery. This can also be combined with methods for nonsmooth mechanics, i.e., systems subject to discontinuities such as impacts, contacts, switching modes, etc.

We have previously developed methods for rigid multibody with frictional contacts, non-smooth hydraulics and non-smooth electronics, all of which turned out to be much faster than available software packages for the same level of accuracy.

Extending this to include electrical motors will allow for comprehensive simulation of robots for instance, but also electric cars and such.

Multibody dynamics modeling of bacterial biofilm

Simple adaptive time step for low order stepping scheme

Jamming phenomena in flowing granular media

Benchmarking of frictional contact solvers

Graph partitioning and load balancing for sparse matrix solvers

Merging and splitting bodies dynamically

Simulating ships moving in shallow waters

Added mass computations

Stable joint kinematics using Euler angles

Modeling hydraulic components with non-smooth methods

Modeling tracked vehicles on soft terrain

Control of granular systems

Previous projects

  • Projected conjugate-gradient solver for contacting rigid bodies on GPGPU
  • Parallel projected Gauss-Seidel solver for large-scale granular matter - Examining the physics of the parallel solver and development of a multigrid solver (Johan Sundberg)
  • Discrete time variational mechanics of multidomain systems: Applications to coupled electronic, hydraulic, and multibody systems (Tomas Sjöström)
  • A Parallel Blocked Multifrontal Implementation of Colesky Factorization for Sparse Matrices (Olof Sabelström)
  • A constraint based viscoplastic fluid model of granular matter (John Nordberg)
  • Discrete event simulations in forestry technology (Linus Jundén)
  • Constraint Fluids on GPU* (Martin Nilsson)
  • Parallel Simulation of Particle Fluids* (Mattias Linde)
  • Phun* (Emil Ernefeldt)
  • Realtime Simulation of Wires (Fredrik Nordfelth)
  • Real-Time Simulation of Deformable Objects (Niklas Melin)
  • Rigid Body Simulation of Macro Molecules (Christian Svebilius)
  • Simulation of off-road Vehicle (Erik Linder)
  • Shared Control of Mechanical Systems in Virtual Environments (Anders Hansson)
  • Smoothed Particle Hydrodynamics on the Cell Broadband Engine* (Nils Hjelte)
  • Smooth and nonsmooth approaches to simulation of granular matter (Stefan Hedman)
  • ... and several more

'*' was run at VRLab

External projects

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