Empathy List Archives

MR

Matthew Ridzon, PE

Thu, Jul 16, 2026 1:34 PM

Folks,

I'm running ANTYPE,MODAL followed by ANTYPE,SPECTR. I ran a small test to extract FSUM data from the spectrum model. I separately extracted the modal FSUM data and applied the mode coefficients to determine the same data manually, using the SRSS spectrum calculation. Coding SRSS in APDL is not hard to do. However, has anyone coded the CQC calculations in APDL (or in an Excel sheet)? If so, would you be willing to share? CQC looks far more complicated to do by hand.

Matt Ridzon, PE, MSME
Sr. Engineering Analyst

Email matt@prime-engineer.com mailto:matt@prime-engineer.com
Mail 266 Main St, Burlington, VT 05401
Web www.prime-engineer.com http://www.prime-engineer.com/
[A blue hexagon with white letters Description automatically generated]
PRIME ENGINEERING LLC

This message (including any attachments) may contain confidential, proprietary, privileged and/or private information. The information is intended to be for the use of the individual or entity designated above. If you are not the intended recipient of this message, please notify the sender immediately, and delete the message and any attachments. Any disclosure, reproduction, distribution or other use of this message or any attachments by an individual or entity other than the intended recipient is prohibited.

Folks, I'm running ANTYPE,MODAL followed by ANTYPE,SPECTR. I ran a small test to extract FSUM data from the spectrum model. I separately extracted the modal FSUM data and applied the mode coefficients to determine the same data manually, using the SRSS spectrum calculation. Coding SRSS in APDL is not hard to do. However, has anyone coded the CQC calculations in APDL (or in an Excel sheet)? If so, would you be willing to share? CQC looks far more complicated to do by hand. Matt Ridzon, PE, MSME Sr. Engineering Analyst Email matt@prime-engineer.com<mailto:matt@prime-engineer.com> Mail 266 Main St, Burlington, VT 05401 Web www.prime-engineer.com<http://www.prime-engineer.com/> [A blue hexagon with white letters Description automatically generated] PRIME ENGINEERING LLC This message (including any attachments) may contain confidential, proprietary, privileged and/or private information. The information is intended to be for the use of the individual or entity designated above. If you are not the intended recipient of this message, please notify the sender immediately, and delete the message and any attachments. Any disclosure, reproduction, distribution or other use of this message or any attachments by an individual or entity other than the intended recipient is prohibited.

DG

David Gross

Sat, Jul 18, 2026 9:00 PM

Matt,

This question confuses me. Are you not simply invoking the ANSYS APDL command to perform the CQC mode combinations automatically (i.e., CQC command)?

Regards,

-----Original Message-----
From: Matthew Ridzon, PE via Xansys xansys-temp@list.xansys.org
Sent: Thursday, July 16, 2026 6:34 AM
To: XANSYS Mailing List Home xansys-temp@list.xansys.org
Cc: Matthew Ridzon, PE Matt@prime-engineer.com
Subject: [Xansys] CQC Spectrum Method

Folks,

I'm running ANTYPE,MODAL followed by ANTYPE,SPECTR. I ran a small test to extract FSUM data from the spectrum model. I separately extracted the modal FSUM data and applied the mode coefficients to determine the same data manually, using the SRSS spectrum calculation. Coding SRSS in APDL is not hard to do. However, has anyone coded the CQC calculations in APDL (or in an Excel sheet)? If so, would you be willing to share? CQC looks far more complicated to do by hand.

Matt Ridzon, PE, MSME
Sr. Engineering Analyst

Email matt@prime-engineer.com mailto:matt@prime-engineer.com
Mail 266 Main St, Burlington, VT 05401
Web www.prime-engineer.com http://www.prime-engineer.com/
[A blue hexagon with white letters Description automatically generated] PRIME ENGINEERING LLC

This message (including any attachments) may contain confidential, proprietary, privileged and/or private information. The information is intended to be for the use of the individual or entity designated above. If you are not the intended recipient of this message, please notify the sender immediately, and delete the message and any attachments. Any disclosure, reproduction, distribution or other use of this message or any attachments by an individual or entity other than the intended recipient is prohibited.

*** WARNING: This email originated from outside of the organization. Exercise caution when viewing attachments, clicking links, or responding to requests. ***

Matt, This question confuses me. Are you not simply invoking the ANSYS APDL command to perform the CQC mode combinations automatically (i.e., CQC command)? Regards, David J. Gross, P.E., ASME Fellow | Dominion Engineering, Inc. Technical Executive 12100 Sunrise Valley Drive, Suite 220 | Reston, VA 20191 office 703.657.7300 | desk 703.657.7311 | mobile 301.580.3066 dgross@domeng.com | domeng.com -----Original Message----- From: Matthew Ridzon, PE via Xansys <xansys-temp@list.xansys.org> Sent: Thursday, July 16, 2026 6:34 AM To: XANSYS Mailing List Home <xansys-temp@list.xansys.org> Cc: Matthew Ridzon, PE <Matt@prime-engineer.com> Subject: [Xansys] CQC Spectrum Method Folks, I'm running ANTYPE,MODAL followed by ANTYPE,SPECTR. I ran a small test to extract FSUM data from the spectrum model. I separately extracted the modal FSUM data and applied the mode coefficients to determine the same data manually, using the SRSS spectrum calculation. Coding SRSS in APDL is not hard to do. However, has anyone coded the CQC calculations in APDL (or in an Excel sheet)? If so, would you be willing to share? CQC looks far more complicated to do by hand. Matt Ridzon, PE, MSME Sr. Engineering Analyst Email matt@prime-engineer.com<mailto:matt@prime-engineer.com> Mail 266 Main St, Burlington, VT 05401 Web www.prime-engineer.com<http://www.prime-engineer.com/> [A blue hexagon with white letters Description automatically generated] PRIME ENGINEERING LLC This message (including any attachments) may contain confidential, proprietary, privileged and/or private information. The information is intended to be for the use of the individual or entity designated above. If you are not the intended recipient of this message, please notify the sender immediately, and delete the message and any attachments. Any disclosure, reproduction, distribution or other use of this message or any attachments by an individual or entity other than the intended recipient is prohibited. *** WARNING: This email originated from outside of the organization. Exercise caution when viewing attachments, clicking links, or responding to requests. ***

MR

Matthew Ridzon, PE

Mon, Jul 20, 2026 4:17 PM

David,

Sorry for the confusion. Your understanding is incorrect; i.e., this is not a question about invoking the CQC command. I'll attempt to clarify...

I'm doing a manual comparison of FSUM data at a location on a model. I'm manually extracting FSUM data from the modal analysis for every mode at a location. I then manually extract the modal coefficients from the spectrum analysis using *GET. With some basic APDL math scripting, I manually multiply the modal FSUM data of each mode, by its corresponding modal coefficient. Then in the last step, I SRSS all of those values to get the actual FSUM data for the location. It matches what I get if I just issue FSUM from the spectrum analysis. In this scenario, the spectrum analysis uses the SRSS method.

Next, I want to redo the manual verification of the FSUM data using CQC method instead. But coding the basic math of CQC is more complicated. I would like to know if anyone has coded the CQC math before.

I hope that explains it better.

-Matt

-----Original Message-----
From: David Gross via Xansys xansys-temp@list.xansys.org
Sent: Saturday, July 18, 2026 5:00 PM
To: XANSYS Mailing List Home xansys-temp@list.xansys.org
Cc: David Gross dgross@domeng.com
Subject: [Xansys] Re: CQC Spectrum Method

CAUTION: This email originated from outside Prime Engineering. Use caution before clicking links or opening attachments. Verify that you recognize the sender and were expecting the message. Never provide credentials.

Matt,

This question confuses me. Are you not simply invoking the ANSYS APDL command to perform the CQC mode combinations automatically (i.e., CQC command)?

Regards,

-----Original Message-----
From: Matthew Ridzon, PE via Xansys xansys-temp@list.xansys.org
Sent: Thursday, July 16, 2026 6:34 AM
To: XANSYS Mailing List Home xansys-temp@list.xansys.org
Cc: Matthew Ridzon, PE Matt@prime-engineer.com
Subject: [Xansys] CQC Spectrum Method

Folks,

I'm running ANTYPE,MODAL followed by ANTYPE,SPECTR. I ran a small test to extract FSUM data from the spectrum model. I separately extracted the modal FSUM data and applied the mode coefficients to determine the same data manually, using the SRSS spectrum calculation. Coding SRSS in APDL is not hard to do. However, has anyone coded the CQC calculations in APDL (or in an Excel sheet)? If so, would you be willing to share? CQC looks far more complicated to do by hand.

Matt Ridzon, PE, MSME
Sr. Engineering Analyst

Email matt@prime-engineer.com mailto:matt@prime-engineer.com
Mail 266 Main St, Burlington, VT 05401
Web www.prime-engineer.com http://www.prime-engineer.com/
[A blue hexagon with white letters Description automatically generated] PRIME ENGINEERING LLC

This message (including any attachments) may contain confidential, proprietary, privileged and/or private information. The information is intended to be for the use of the individual or entity designated above. If you are not the intended recipient of this message, please notify the sender immediately, and delete the message and any attachments. Any disclosure, reproduction, distribution or other use of this message or any attachments by an individual or entity other than the intended recipient is prohibited.

*** WARNING: This email originated from outside of the organization. Exercise caution when viewing attachments, clicking links, or responding to requests. *** _______________________________________________
Xansys mailing list -- xansys-temp@list.xansys.org To unsubscribe send an email to xansys-temp-leave@list.xansys.org If you are receiving too many emails from XANSYS please consider changing account settings to Digest mode which will send a single email per day.

Please send administrative requests such as deletion from XANSYS to xansys-mod@tynecomp.co.uk and not to the list

David, Sorry for the confusion. Your understanding is incorrect; i.e., this is not a question about invoking the CQC command. I'll attempt to clarify... I'm doing a manual comparison of FSUM data at a location on a model. I'm manually extracting FSUM data from the modal analysis for every mode at a location. I then manually extract the modal coefficients from the spectrum analysis using *GET. With some basic APDL math scripting, I manually multiply the modal FSUM data of each mode, by its corresponding modal coefficient. Then in the last step, I SRSS all of those values to get the actual FSUM data for the location. It matches what I get if I just issue FSUM from the spectrum analysis. In this scenario, the spectrum analysis uses the SRSS method. Next, I want to redo the manual verification of the FSUM data using CQC method instead. But coding the basic math of CQC is more complicated. I would like to know if anyone has coded the CQC math before. I hope that explains it better. -Matt -----Original Message----- From: David Gross via Xansys <xansys-temp@list.xansys.org> Sent: Saturday, July 18, 2026 5:00 PM To: XANSYS Mailing List Home <xansys-temp@list.xansys.org> Cc: David Gross <dgross@domeng.com> Subject: [Xansys] Re: CQC Spectrum Method CAUTION: This email originated from outside Prime Engineering. Use caution before clicking links or opening attachments. Verify that you recognize the sender and were expecting the message. Never provide credentials. Matt, This question confuses me. Are you not simply invoking the ANSYS APDL command to perform the CQC mode combinations automatically (i.e., CQC command)? Regards, David J. Gross, P.E., ASME Fellow | Dominion Engineering, Inc. Technical Executive 12100 Sunrise Valley Drive, Suite 220 | Reston, VA 20191 office 703.657.7300 | desk 703.657.7311 | mobile 301.580.3066 dgross@domeng.com | domeng.com -----Original Message----- From: Matthew Ridzon, PE via Xansys <xansys-temp@list.xansys.org> Sent: Thursday, July 16, 2026 6:34 AM To: XANSYS Mailing List Home <xansys-temp@list.xansys.org> Cc: Matthew Ridzon, PE <Matt@prime-engineer.com> Subject: [Xansys] CQC Spectrum Method Folks, I'm running ANTYPE,MODAL followed by ANTYPE,SPECTR. I ran a small test to extract FSUM data from the spectrum model. I separately extracted the modal FSUM data and applied the mode coefficients to determine the same data manually, using the SRSS spectrum calculation. Coding SRSS in APDL is not hard to do. However, has anyone coded the CQC calculations in APDL (or in an Excel sheet)? If so, would you be willing to share? CQC looks far more complicated to do by hand. Matt Ridzon, PE, MSME Sr. Engineering Analyst Email matt@prime-engineer.com<mailto:matt@prime-engineer.com> Mail 266 Main St, Burlington, VT 05401 Web www.prime-engineer.com<http://www.prime-engineer.com/> [A blue hexagon with white letters Description automatically generated] PRIME ENGINEERING LLC This message (including any attachments) may contain confidential, proprietary, privileged and/or private information. The information is intended to be for the use of the individual or entity designated above. If you are not the intended recipient of this message, please notify the sender immediately, and delete the message and any attachments. Any disclosure, reproduction, distribution or other use of this message or any attachments by an individual or entity other than the intended recipient is prohibited. *** WARNING: This email originated from outside of the organization. Exercise caution when viewing attachments, clicking links, or responding to requests. *** _______________________________________________ Xansys mailing list -- xansys-temp@list.xansys.org To unsubscribe send an email to xansys-temp-leave@list.xansys.org If you are receiving too many emails from XANSYS please consider changing account settings to Digest mode which will send a single email per day. Please send administrative requests such as deletion from XANSYS to xansys-mod@tynecomp.co.uk and not to the list

DG

David Gross

Mon, Jul 20, 2026 4:49 PM

Matt,

Makes total sense now, and no, I've not had to do a hand-check of a modal combination since CQC became the method preferred by USNRC some time ago. However, as luck would have it, one of my colleagues is just getting started a seismic response analysis now and will probably be wanting to do a similar exercise as part of our required "sanity checks" at the end of the analysis. If you come up with something (either yourself or from this list), I would appreciate if I could get a copy from you.

Regards,

David

-----Original Message-----
From: Matthew Ridzon, PE Matt@prime-engineer.com
Sent: Monday, July 20, 2026 9:17 AM
To: XANSYS Mailing List Home xansys-temp@list.xansys.org
Cc: David Gross dgross@domeng.com
Subject: RE: CQC Spectrum Method

David,

Sorry for the confusion. Your understanding is incorrect; i.e., this is not a question about invoking the CQC command. I'll attempt to clarify...

I'm doing a manual comparison of FSUM data at a location on a model. I'm manually extracting FSUM data from the modal analysis for every mode at a location. I then manually extract the modal coefficients from the spectrum analysis using *GET. With some basic APDL math scripting, I manually multiply the modal FSUM data of each mode, by its corresponding modal coefficient. Then in the last step, I SRSS all of those values to get the actual FSUM data for the location. It matches what I get if I just issue FSUM from the spectrum analysis. In this scenario, the spectrum analysis uses the SRSS method.

Next, I want to redo the manual verification of the FSUM data using CQC method instead. But coding the basic math of CQC is more complicated. I would like to know if anyone has coded the CQC math before.

I hope that explains it better.

-Matt

-----Original Message-----
From: David Gross via Xansys xansys-temp@list.xansys.org
Sent: Saturday, July 18, 2026 5:00 PM
To: XANSYS Mailing List Home xansys-temp@list.xansys.org
Cc: David Gross dgross@domeng.com
Subject: [Xansys] Re: CQC Spectrum Method

CAUTION: This email originated from outside Prime Engineering. Use caution before clicking links or opening attachments. Verify that you recognize the sender and were expecting the message. Never provide credentials.

Matt,

This question confuses me. Are you not simply invoking the ANSYS APDL command to perform the CQC mode combinations automatically (i.e., CQC command)?

Regards,

-----Original Message-----
From: Matthew Ridzon, PE via Xansys xansys-temp@list.xansys.org
Sent: Thursday, July 16, 2026 6:34 AM
To: XANSYS Mailing List Home xansys-temp@list.xansys.org
Cc: Matthew Ridzon, PE Matt@prime-engineer.com
Subject: [Xansys] CQC Spectrum Method

Folks,

I'm running ANTYPE,MODAL followed by ANTYPE,SPECTR. I ran a small test to extract FSUM data from the spectrum model. I separately extracted the modal FSUM data and applied the mode coefficients to determine the same data manually, using the SRSS spectrum calculation. Coding SRSS in APDL is not hard to do. However, has anyone coded the CQC calculations in APDL (or in an Excel sheet)? If so, would you be willing to share? CQC looks far more complicated to do by hand.

Matt Ridzon, PE, MSME
Sr. Engineering Analyst

Email matt@prime-engineer.com mailto:matt@prime-engineer.com
Mail 266 Main St, Burlington, VT 05401
Web www.prime-engineer.com http://www.prime-engineer.com/
[A blue hexagon with white letters Description automatically generated] PRIME ENGINEERING LLC

This message (including any attachments) may contain confidential, proprietary, privileged and/or private information. The information is intended to be for the use of the individual or entity designated above. If you are not the intended recipient of this message, please notify the sender immediately, and delete the message and any attachments. Any disclosure, reproduction, distribution or other use of this message or any attachments by an individual or entity other than the intended recipient is prohibited.

*** WARNING: This email originated from outside of the organization. Exercise caution when viewing attachments, clicking links, or responding to requests. *** _______________________________________________
Xansys mailing list -- xansys-temp@list.xansys.org To unsubscribe send an email to xansys-temp-leave@list.xansys.org If you are receiving too many emails from XANSYS please consider changing account settings to Digest mode which will send a single email per day.

Please send administrative requests such as deletion from XANSYS to xansys-mod@tynecomp.co.uk and not to the list
*** WARNING: This email originated from outside of the organization. Exercise caution when viewing attachments, clicking links, or responding to requests. ***

Matt, Makes total sense now, and no, I've not had to do a hand-check of a modal combination since CQC became the method preferred by USNRC some time ago. However, as luck would have it, one of my colleagues is just getting started a seismic response analysis now and will probably be wanting to do a similar exercise as part of our required "sanity checks" at the end of the analysis. If you come up with something (either yourself or from this list), I would appreciate if I could get a copy from you. Regards, David -----Original Message----- From: Matthew Ridzon, PE <Matt@prime-engineer.com> Sent: Monday, July 20, 2026 9:17 AM To: XANSYS Mailing List Home <xansys-temp@list.xansys.org> Cc: David Gross <dgross@domeng.com> Subject: RE: CQC Spectrum Method David, Sorry for the confusion. Your understanding is incorrect; i.e., this is not a question about invoking the CQC command. I'll attempt to clarify... I'm doing a manual comparison of FSUM data at a location on a model. I'm manually extracting FSUM data from the modal analysis for every mode at a location. I then manually extract the modal coefficients from the spectrum analysis using *GET. With some basic APDL math scripting, I manually multiply the modal FSUM data of each mode, by its corresponding modal coefficient. Then in the last step, I SRSS all of those values to get the actual FSUM data for the location. It matches what I get if I just issue FSUM from the spectrum analysis. In this scenario, the spectrum analysis uses the SRSS method. Next, I want to redo the manual verification of the FSUM data using CQC method instead. But coding the basic math of CQC is more complicated. I would like to know if anyone has coded the CQC math before. I hope that explains it better. -Matt -----Original Message----- From: David Gross via Xansys <xansys-temp@list.xansys.org> Sent: Saturday, July 18, 2026 5:00 PM To: XANSYS Mailing List Home <xansys-temp@list.xansys.org> Cc: David Gross <dgross@domeng.com> Subject: [Xansys] Re: CQC Spectrum Method CAUTION: This email originated from outside Prime Engineering. Use caution before clicking links or opening attachments. Verify that you recognize the sender and were expecting the message. Never provide credentials. Matt, This question confuses me. Are you not simply invoking the ANSYS APDL command to perform the CQC mode combinations automatically (i.e., CQC command)? Regards, David J. Gross, P.E., ASME Fellow | Dominion Engineering, Inc. Technical Executive 12100 Sunrise Valley Drive, Suite 220 | Reston, VA 20191 office 703.657.7300 | desk 703.657.7311 | mobile 301.580.3066 dgross@domeng.com | domeng.com -----Original Message----- From: Matthew Ridzon, PE via Xansys <xansys-temp@list.xansys.org> Sent: Thursday, July 16, 2026 6:34 AM To: XANSYS Mailing List Home <xansys-temp@list.xansys.org> Cc: Matthew Ridzon, PE <Matt@prime-engineer.com> Subject: [Xansys] CQC Spectrum Method Folks, I'm running ANTYPE,MODAL followed by ANTYPE,SPECTR. I ran a small test to extract FSUM data from the spectrum model. I separately extracted the modal FSUM data and applied the mode coefficients to determine the same data manually, using the SRSS spectrum calculation. Coding SRSS in APDL is not hard to do. However, has anyone coded the CQC calculations in APDL (or in an Excel sheet)? If so, would you be willing to share? CQC looks far more complicated to do by hand. Matt Ridzon, PE, MSME Sr. Engineering Analyst Email matt@prime-engineer.com<mailto:matt@prime-engineer.com> Mail 266 Main St, Burlington, VT 05401 Web www.prime-engineer.com<http://www.prime-engineer.com/> [A blue hexagon with white letters Description automatically generated] PRIME ENGINEERING LLC This message (including any attachments) may contain confidential, proprietary, privileged and/or private information. The information is intended to be for the use of the individual or entity designated above. If you are not the intended recipient of this message, please notify the sender immediately, and delete the message and any attachments. Any disclosure, reproduction, distribution or other use of this message or any attachments by an individual or entity other than the intended recipient is prohibited. *** WARNING: This email originated from outside of the organization. Exercise caution when viewing attachments, clicking links, or responding to requests. *** _______________________________________________ Xansys mailing list -- xansys-temp@list.xansys.org To unsubscribe send an email to xansys-temp-leave@list.xansys.org If you are receiving too many emails from XANSYS please consider changing account settings to Digest mode which will send a single email per day. Please send administrative requests such as deletion from XANSYS to xansys-mod@tynecomp.co.uk and not to the list *** WARNING: This email originated from outside of the organization. Exercise caution when viewing attachments, clicking links, or responding to requests. ***