Structural analysis system

A system for determining the modal characteristics of a structure comprising:

• a plurality of shakers coupled to said structure;
• means for selectively applying to said shakers a plurality of driving signals having a common preselected complex frequency and a preselected set of amplitudes and phases corresponding to a mode of interest;
• means for termininating said driving signals;
• means for sensing the response of said structure to said driving signals;
• means for receiving said sensed response and for generating a set of transfer functions in the complex frequency domain characteristic of said structure corresponding to said mode of interest, said set of transfer functions containing the complex frequencies and complex residues of said mode of interest;
• and
• means for sorting said complex frequencies and said complex residues to obtain a complex frequency and a set of amplitudes and phases corresponding to said mode of interest.

A method of determining the modal characteristics of a structure comprising the steps of:

• applying to said structure a plurality of driving signals having a common preselected complex frequency and a preselected set of amplitudes and phases corresponding to a mode of interest;
• sensing the response of said structure to said driving signals;
• generating from said driving signals and said sensed response a set of transfer functions containing the complex frequencies and complex residues of said modes of interest of said structure;
• and
• sorting said complex frequencies and complex residues to obtain a complex frequency and a set of amplitudes and phases corresponding to said mode of interest.

A method of determining the modal characteristics of a structure comprising the steps of:

• applying to said structure a plurality of driving signals having a common preselected complex frequency and a preselected set of amplitudes and phases corresponding to a mode of interest;
• terminating said driving signals;
• sensing the response of said structure to said driving signals;
• generating from said sensed response a set of transfer functions containing the complex frequencies and complex residues of said modes of interest of said structure;
• and
• sorting said complex frequencies and complex residues to obtain a complex frequency and a set of amplitudes and phases corresponding to said mode of interest.

A system for determining the modal characteristics of a structure comprising:

• means for utilizing a plurality of driving signals having a common preselected complex frequency and a preselected set of amplitudes and phases corresponding to a mode of interest to apply a preselected spatial distribution of forces to said structure;
• means for sensing the response of said structure to said forces;
• means for receiving said driving signals and said sensed response and for generating a set of transfer functions in the complex frequency domain characteristic of said structure corresponding to said mode of interest, said set of transfer functions containing the complex frequencies and complex residues of said mode of interest;
• and
• means for sorting said complex frequencies and said complex residues to obtain a complex frequency and set of amplitudes and phases corresponding to said mode of interest.

A system for determining the modal characteristics of a structure comprising:

• means for utilizing a plurality of driving signals having a common preselected complex frequency and a preselected set of amplitudes and phases corresponding to a mode of interest to apply a preselected spatial distribution of forces to said structure;
• means for terminating said forces;
• means for sensing the response of said structure to said forces;
• means for receiving said sensed response and for generating a set of transfer functions in the complex frequency domain characteristic of said structure corresponding to said mode of interest, said set of transfer functions containing the complex frequencies and said complex residues of said mode of interest;
• and
• means for sorting said complex frequencies and said complex residues to obtain a complex frequency and set of amplitudes and phases corresponding to said mode of interest.

A system for determining the modal characteristics of a structure comprising:

• means for generating a plurality of driving signals having a common preselected complex frequency and a preselected set of amplitudes and phases corresponding to a mode of interest to apply a preselected set of excitations to said structure;
• means for applying said excitations to said structure;
• and
• means for sensing the response of said structure to said excitations.

A system for determining the modal characteristics of a structure comprising:

• means for generating a plurality of driving signals having a common preselected complex frequency corresponding to a mode of interest to apply a set of excitations to said structure;
• means for applying said excitations to said structure;
• and
• means for sensing the response of said structure to said excitations.

A method of determining the modal characteristics of a structure comprising the steps of:

• generating a plurality of driving signals having a common preselected complex frequency and a preselected set of amplitudes and phases corresponding to a mode of interest to apply a preselected set of excitations to such structure;
• applying said excitations to said structure;
• and
• sensing the response of said structure to said excitations.

A method of determining the modal characteristics of a structure comprising the steps of:

• generating a plurality of driving signals having a common preselected complex frequency and a preselected set of amplitudes and phases corresponding to a mode of interest to apply a preselected set of excitations to said structure;
• applying said excitations to said structure;
• terminating said excitations;
• and
• sensing the response of said structure to said excitations.

A system for determining the modal characteristics of a structure comprising:

• means for generating a plurality of driving signals having a common preselected complex frequency and a preselected set of amplitudes and phases corresponding to a mode of interest to apply a set of excitations to said structure;
• means for applying said excitations to said structure;
• means for terminating said excitations;
• and
• means for sensing the response of said structure to said excitations, the complex frequency of said driving signals and the individual magnitude and phase of each of said driving signals being selected to induce a substantially pure mode of said structure.