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New Features in PERMAS Version 15

New in Version 15

The new Version 15 of PERMAS is the result of about 24 months of development work. For a complete and detailed overview on changes, a Software Release Note is shipped with Version 15.
Great effort has been spent in the past years to provide with VisPER (i.e. Visual PERMAS) a dedicated tool to improve pre- and post-processing for special PERMAS functions. The fourth regular VisPER Version 4 is released at the same time as PERMAS Version 15.

PERMAS V15 offers again improved computing performance:
  • The reordering process has been improved and parallelized which reduces the run time for large models significantly.
  • Improved algorithm for direct fluid-structure coupled frequency response analysis.
  • Performance improvements are made for contact analysis in case of friction. A better convergence in frictional force iterations can lead to a significant run time reduction dependent on the model characteristics.
  • Further acceleration of compute-bound analyses by utilizing Nvidia Tesla GPUs (K20c or better) in addition to standard SMP parallelization.

New Module
  • The new module XPU supports Nvidia GPU acceleration cards (Tesla K20/40 with CUDA Version 6) by a seamless integration in PERMAS parallelization concept. The acceleration will be most beneficial for compute-bound analysis, such as eigenvalue analysis with a high number of modes, a direct fluid-structure coupled response analysis, or large normal contact problems.

Major extensions
  • Extensions to Basic Module (Module MQA):
    • In order to investigate the influence of certain parameters of a model on the results, a new sampling analysis feature has been integrated. Sampling is the repeated execution of analyses where the values of design or basic variables are specified explicitly. Sampling works analogous to optimization and reliability analysis. So, all possible design or basic variables can be used for sampling and all analysis steps supported by optimization and reliability analysis can be used for sampling as well. For all desired results, sampling collects this data and prepares special XY data for convenient post-processing. Some examples for suitable variables are geometric parameters, Young's modulus for stiffness considerations, or different load parameters.
  • Extensions to Contact Analysis (Modules CA/CAX/CAU):
    • Self contact is now supported by contact analysis, i.e. contact models where a surface may get in touch with itself, e.g. due to warping or other forms of large deformations, and where contacting regions are not known in advance.
    • Contacting bodies are often only supported by contact forces. To provide an elastic foundation to such bodies, a new family of compensation springs (also called zero force springs) has been introduced, where the spring force is compensated by an additional contact force. By this means, a force-guided contact is facilitated. In addition, the new RBM Assistant in VisPER helps to place and properly define such elements.
    • For the linearization of contacts to perform a subsequent linear analysis (like vibration analysis), various thresholds for the locking of contacts are available. E.g., the locking can be made dependent on a threshold of the contact pressure. Beyond this pressure value, a coupling is performed, below this threshold no coupling takes place. Frequently, contact analysis and subsequent linear analysis (like vibration analysis) are made in separate runs. To support this, contact status files from contact analysis can be used by subsequent runs to generate the locking of contacts.
    • Contact geometry update has been made more stable and faster. One measure was to extend the contact status files to take geometry update into account.
  • Extensions to Nonlinear Static Analysis (Module NLS):
    • PERMAS provides two different solvers for nonlinear static analysis according to the degree of non-linearities involved: NLMATERIAL/NLINERTIA and STATIC/INERTIA. Now, STATIC/INERTIA has been extended to take temperature-dependent material into account, too. In addition, special algorithmic improvements give STATIC/INERTIA in those cases a high potential for run time savings compared to NLMATERIAL/NLINERTIA.
    • A new post-buckling feature has been integrated. This allows the static analysis beyond buckling. In addition, after nonlinear analysis a linear buckling can be performed to study all possible buckling modes at this point of loading.
    • Geometrically nonlinear calculations can now be also made for composite and sandwich materials (with elements SHELL3 and SHELL4 for composites and elements TRIA3S and QUAD4S for sandwich shells). This includes buckling and post-buckling capabilities.
  • Extensions to Dynamic Eigenvalue Analysis (Module DEV):
    • Nonstructural masses can be assigned to solid elements. Beside absolute mass values, mass per volume can also be specified.
  • Extensions to Dynamic Eigenvalue Analysis with MLDR (Module MLDR):
    • Additional matrices like geometrical stiffness can now also be taken into account.
    • Additional static mode shapes can now be additionally taken into account in the top component.
  • Extensions to Extended Dynamic Eigenvalue Analysis (Module DEVX):
    • Backtransformation after complex eigenvalue analysis can be reduced to a subset of modes.
  • Extensions to Dynamic Response Analysis (Modules DRA):
    • Modal response analysis in time and frequency domain can be used to provide loading matrices to enhance matrix models.
  • Extensions to Fluid-Structure Acoustics (Modules FS):
    • Coupled vibration analysis and modal coupled frequency response analysis support automatic substructuring and results in the top component.
    • Additional static mode shapes can now be additionally taken into account.
  • Extensions to Design Optimization (Modules OPT):
    • A new non-parametric optimization feature has been integrated which allows a free-form shape optimization of structures for minimizing stresses by homogenization or for limiting stresses at minimum weight. This opens the most easy way to define shape optimization of free-form geometries. The set-up of this optimization is supported by a new freeshape wizard in VisPER.
    • Design constraint linking has been introduced as powerful tool to build constraint equations for multiple result values.
  • Extensions to Topology Optimization (Module TOPO):
    • Topology optimization is now able to provide a solution with clear separation of filled and void elements. So, elements will show filling ratios near 0 or near 1. This feature avoids misinterpretation of topology optimization results and facilitates the direct use of the result for further analysis and design steps.
  • Extensions to Advanced Optimization Solvers (Module AOS):
    • Optimization is now also possible for complex eigenvalue analysis (including rotating structures).
    • Design constraint linking has been introduced as powerful tool to build constraint equations for multiple result values.
  • Extensions to Reliability Analysis (Module RA):
    • Reliability analysis is now also possible for complex eigenvalue analysis (including rotating structures).
New Elements
  • A zero force spring family of elements has been introduced to be solely applied in conjunction with contact analysis. The elements can support rigid body modes, but no spring force disturbs the contact force result.
  • Linear load elements and linear 3D shell elements now provide pressure stiffness as additional stiffness effect.
New kinematic constraint conditions
  • For the linearization of surfaces which consists of element faces with quadratic shape functions, a new kinematic constraint (ISURFLIN) is available. This feature can be used e.g. to linearize surfaces in case of contact.
  • For the interpolation of values in a volume, a new kinematic constraint is available (IVOLUME). This can be used e.g. for the generation of results at points where no element nodes are available.
Other extensions
Many smaller extensions of almost all functional modules had been performed in addition. Moreover, all interfaces were updated and adapted to the new functionalities. Most important interface enhancements are:
  • Medina
    • Support of MEDINA 8.4.2.
    • Self contact definition enabled.
    • Export of new PERMAS Version 15 results.
  • Nastran
    • An option is provided to generate QUAMS elements instead of QUAD elements.
    • Support of pyramid elements.
    • Extended support of OUTPUT2 format.
  • Abaqus
    • Extended interface for mass, beam, membrane and connector elements.
    • Support of pre-tension section.
    • Additional loads: centrifugal, gravity and surface pressure.
    • Support of steady-state heat transfer analysis, eigenfrequency analysis, dynamic frequency response analysis.
  • Hyperview
    • Support of HyperView 11.0 Libraries.
    • Post-processing on HyperView 8.0 libraries possible.
    • Export of new PERMAS Version 15 results.

For all system platforms an update to the current release of the operating system had been performed.