Ingenieurgesellschaft für
technische Software

Engine Analysis with PERMAS

A number of effects of physics have to be considered when analysing combustion engines mechanically. In static analysis, seal tightness and strength analysis during changing temperatures play an important role, whereas dynamic analysis takes a closer look at sound radiation and frequency responses of the engine’s hang-on-parts. In static analysis, heat transfer has to be taken into account which requires a paired analysis to allow for the influence of temperature. During engine assembly, the bolt’s preload force has to be taken into account, and in order to determine the ideal point of bolt tightening as well as maximum operating load, a precise simulation of bolt loading sequences has to be carried out. Additionally, the effects of non-linear material behaviour have to be factored in. Each of these as well as additional effects have to be considered when analysing combustion engines. A freeform optimization facilitates a reduction in weight with improved product performance.
Benefits and particular strengths
PERMAS performance aspects
Due to the models for engine analysis usually being complex, our strategies are geared towards maximum efficiency. The following aspects should be emphasized:
  • significantly shorter computing times than you would expect or that you are used to (we are up to the challenge:,
  • Shorter computing times mean reducing costs for both software and hardware, quicker product cycles, more variation, better knowledge on behaviour of specific parts and improved products.
  • Contact algorithms designed for big and complex models,
  • Calculation times of non-linear sealing elements similar to linear models due to specialised solvers allowing for automatic condensation,
  • Acceleration of variant analysis and optimization owing to preconditioned contact solvers,
  • extremely fast thanks to PERMAS HPC fundamental technology, such as contact analysis, parallelization, and GPU-usage.
Heat Transfer
Heat Transfer
Calculation of operating temperatures and tempering in oil baths by simulating the processes of cooling down are just a few examples of application.
  • Available features:
    • Nonlinear material behavior with temperature-dependent conductivity and heat capacity,
    • Modelling of temperature-dependent heat transfer to establish heat exchange with the surroundings,
    • Fully automated solution procedure for nonlinear heat transfer with automatic step control as well as several convergence criteria, i.e. an automated algorithm for load stepping when stationary and an automated algorithm for time stepping when transient,
    • Convenient and extremely detailed description model for loading steps and points in time with specified moments of scoring,
    • Fully linked to static analysis (stationary and transient),
    • Temperature calculation can allow for influencing factors to heat exchange such as thermal radiation.
Diesel Engine
1 1/2 cylinder engine model (hex mesh)
Bolt Pretension with pitch and flank angle
Bolt Pretension with pitch and
flank angle
Static analysis with PERMAS
Static deformation is calculated under various loads with linear and nonlinear material behavior:
  • Nonlinear material models:
    • Plastic deformation,
    • Nonlinear elastic,
    • Creep,
    • Grey cast iron with varying material behaviour under tension and compression.
  • Gasket elements:
    • Convenient simulation of seals,
    • Behaviour is described with graphs measuring the relation between pressure-closure curves,
    • Possibility to use a myriad of unloading curves.
  • Contact analysis:
    • many contacts possible (>>30,000),
    • unrivaled short run times,
    • most advanced solver technology,
    • friction can be taken into account with transitions between sticking and sliding,
    • bolt conditions can be applied in one step,
    • description of a realistic loading history,
    • contact results: contact pressure, contact status, contact forces, saturation, etc.
  • Modeling:
    • bolt pretension with parametrized thread,
    • press fit modeling linear and non linear,
  • Submodeling:
    • for subsequent local mesh refinements,
    • automatic interpolation of displacements to get kinematic boundary conditions for a finer mesh,
    • then, a local analysis is performed e.g. to achieve more accurate stresses.
PERMAS performance aspects
Due to the models for engine analysis usually being complex, our strategies are geared towards maximum efficiency. We emphasise the following aspects in particular:
  • Outstanding performance through special algorithms for large models with nonlinear material and contact,
  • Contact algorithms are specifically designed for large models with many contacts,
  • Unrivaled fast method for linear material and contact.
Vibro-Acoustics with PERMAS
One structural model suffices as the same software is being used for both dynamic and static simulations. All dynamic methods are available for engine analysis. A few important features to be considered are the following:
  • MLDR for calculation of eigenvalues and mode shapes for large solid models.
  • Fast dynamic condensation methods support the efficient analysis of engines with many attached parts.
  • Dry condensation allows for the integration of fluids into a mechanical model without factoring in the rate of pressure latitude (for example the oil trough).
  • Calculation of sound particle velocity is supported for the evaluation of noise emission of engines.
Engine with bolts and cylinder head gasket
Gasket with pressure result
valve train
Static analysis of valve train with
large rotation
Questions? Ask us!

INTES Ingenieurgesellschaft für technische Software mbH
Management:  Rolf Fischer
Breitwiesenstr. 28
70565 Stuttgart
Commercial register:  Stuttgart HRB 10 978
VAT registration number: DE 147803245
Tel.: +49 711 78499-0

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