Frequency Domain Structural Analysis Of A Product Having Frequency-Dependent Material Property

A system for conducting frequency-domain structural analysis of a product made of at least in-part frequency-dependent material comprising:

• an input/output (I/O) interface;
• a memory for storing computer readable code for one or more application modules configured for a modified mode-superposition technique in frequency-domain structural analysis;
• at least one processor coupled to the memory, said at least one processor executing the computer readable code in the memory to cause said one or more application modules to perform operations of:
• receiving a finite element analysis (FEA) model representing the product subjected to external harmonic excitations and the external harmonic excitations being defined in a range of external excitation frequencies;
• partitioning the range of frequencies into N frequency bands based on a predefined criterion, wherein N is a whole number greater than one;
• designating a representative frequency for material property calculations and an eigensolution frequency range for upper and lower limits of subsequent eigensolution in each of the N frequency bands;
• extracting N sets of natural vibration frequencies and associated mode shapes by performing N eigensolutions in respective N frequency bands, each eigensolution using the FEA model with material properties calculated from the corresponding representative frequency and using the upper and lower limits of the corresponding eigensolution frequency range of said each of the N frequency bands;
• and
• obtaining steady-state dynamic (SSD) responses of the product via the modified mode-superposition technique that selects and uses corresponding set of the N sets of natural vibration frequencies and mode shapes dependent upon which one of the N frequency bands each of the external harmonic excitations is located.

A non-transitory computer readable storage medium containing instructions for controlling a computer system for conducting frequency-domain structural analysis of a product made of at least in-part frequency-dependent material by a method comprising:

• receiving, in a computer system having one or more application modules installed thereon, a finite element analysis (FEA) model representing the product subjected to external harmonic excitations, the one or more application modules being configured for a modified mode-superposition technique in frequency-domain structural analysis and the external harmonic excitations being defined in a range of external excitation frequencies;
• partitioning, by the one or more application modules, the range of frequencies into N frequency bands based on a predefined criterion, wherein N is a whole number greater than one;
• designating, by the one or more application modules, a representative frequency for material property calculations and an eigensolution frequency range for upper and lower limits of subsequent eigensolution in each of the N frequency bands;
• extracting, by the one or more application modules, N sets of natural vibration frequencies and associated mode shapes by performing N eigensolutions in respective N frequency bands, each eigensolution using the FEA model with material properties calculated from the corresponding representative frequency and using the upper and lower limits of the corresponding eigensolution frequency range of said each of the N frequency bands;
• and
• obtaining, by the one or more application modules, steady-state dynamic (SSD) responses of the product via the modified mode-superposition technique that selects and uses corresponding set of the N sets of natural vibration frequencies and mode shapes dependent upon which one of the N frequency bands each of the external harmonic excitations is located.