MEscope Visual SDM Pro

What is MEscope Visual SDM Pro?

MEscope Visual SDM Pro combines all the features of the Visual Modal Pro package with the features of the VES-5000 Structural Dynamics Modification option. After identifying and quantifying a resonance problem on a machine or structure, the next question is, "How can the structure be modified to fix the problem?"

MEscope Visual SDM Pro helps you quickly evaluate workarounds for resonance problems by adding additional tools to the modal analysis capabilities of a Visual Modal Pro package.

The resonances (vibration modes) of a machine or structure depend on its physical properties (geometry, density, elasticity, boundary conditions). Changing the physical properties of a structure by adding modifications such as reinforcements, supports, tuned dampers, or other modifications will directly affect its modes. The SDM method uses industry-standard finite elements such as springs, masses, dampers, bars, plates, and solids to model modifications. These modifications, along with the modes of the original (unmodified) structure, are used to calculate the new modes of the modified structure.

Example of using MEscope Visual SDM Pro

In the example shown below, a reinforcement was added at the bottom of an aluminum panel. Adding the reinforcement replaced the first mode of the structure (a 73 Hz bending mode) with a torsion mode at 94 Hz. The torsion mode was the second mode of the original structure, but was not affected by rib reinforcement. Without additional reinforcement, nearby machinery operating at 4000-4500 RPM would excite the first bending mode of this panel, making it resonate. Adding the booster not only eliminated the mode at 73 Hz, but also eliminated another mode at 143 Hz, thus also removing a potential resonance problem at 2X RPM.

MEscope Visual SDM Pro Features

Structural Dynamics Modification

• Interactive graphical addition of structural modification elements to a structure model
• All FEA elements visible in a structure model are used by SDM. All hidden elements are ignored
• Modifications can be modeled using the following FEA elements; Point masses, linear springs and linear dampers, rod and beam elements, triangular and quadrilateral plate elements, tetrahedrons, prisms and solid brick elements
• All properties of the FEA element are displayed and edited in property sheets
• Modal sensitivity analysis. Define an FEA property solution space and calculate new modes that minimize differences with target modal properties
• Substructure. Two or more substructures can be connected together with FEA elements, and the modes of the combined substructures calculated
• Absorbents tuned in. Multiple mass-spring-damper vibration absorbers can be attached to a structure model and the new structure modes calculated

Multi-reference modal analysis with MEscope Visual SDM Pro

• Count modes to identify closely coupled modes and repeated roots using the Multi-Reference Complex Mode Indicator (CMIF) function or the multivariate multi-reference mode indicator (MMIF) function
• Curve adjustment using multiple reference orthogonal polynomial method
• Quick adjustment of multiple references. Automatically performs three curve adjustment steps (counting modes, frequency estimation and damping for each mode, residual estimation for each mode) with minimal user interaction
• Multiple reference curve adjustment using a stability diagram and z-polynomial curve adjustment method, complex exponential curve adjustment method, or aliase-free polynomial curve adjustment method (AF Poly)
• Stability A graphical display of frequency and damping estimates (poles) in groups of stable poles with different colors. All poles are calculated using curve adjustment model sizes ranging from 1 to a user-defined maximum
• Stable poles. A graphical display of the poles (frequency and damping estimates) in groups of stable poles with different colors
• Stable pole group. A group of solutions in a stability diagram or poles that satisfy a minimum number of user-defined poles that are within the user-defined damping and frequency tolerances
• Shape complexity graph. A graphical display of complex shape components in one or more modal shapes
• Classification of the magnitude of the shape component. A graphical display of the ordered magnitudes of the shape components of each modal shape
• Shape expansion. A set of shapes with many DOFs is a curve adjustment to a set of shapes with few DOFs, to create new shapes with many DOFs in them
• Poles A graph of the modal frequency and damping estimates (poles) of a set of modal shapes.

MIMO Modeling and Simulation

• MIMO Forced Response: Calculates multiple response time or frequency waveforms (outputs) caused by multiple excitation forces (inputs), using FRFs or mode shapes to model system dynamics
• Forced Response Sinusoidal MIMO. Calculates and displays response shapes (output) caused by multiple sine excitation forces (input), using FRFs or mode shapes to model system dynamics
• MIMO strength path analysis. Calculates multiple excitation force time or frequency waveforms of multiple responses (outputs), using FRFs or mode shapes to model system dynamics
• MIMO FRFs (transfer functions). These frequency functions can be calculated from multiple wave forms of excitation (input) and response (output) time, using rectangular or Hanning time domain windows, trigger, linear, or average peak retention spectrum, and overlay processing
• Multiple and partial coherences. These frequency functions can also be calculated together with MIMO FRFs. Multiple Coherence measures the overall contribution of all measured excitation forces (inputs) for each measured response (output) for each frequency. Partial Coherence measured the contribution of each measured excitation force (input) to each measured response (output) for each frequency.
• MIMO FRFs (transfer functions) can be calculated from multi-channel and automatic frequency spectra

System requirements:

CPU: 1.8 GHz dual core processor

RAM: 2 GB

HDD / SSD: 50 GB of free space on the main drive

Operating system: Microsoft Windows 8 32-bit, Microsoft Windows 7 32-bit and Microsoft Windows Vista 32-bit

Resolution: 1024×768