Modal Analysis - Minimum Initial Strain

Helpful Questions & Answers

  • Frequently Asked Questions (FAQs)

Why do the results in a modal analysis differ between the initial prestress and the surface load?

Answer

In the modal analysis settings, you can set the minimum axial strain for cables and membranes in order to apply an initial prestress to the objects and thus improve the convergence of the calculation. The initial prestress is applied to the objects in a simplified approach.

If you compare this setting with a surface load of the Axial Strain load type, you should pay attention to the fact that the two approaches differ. With the surface load, you perform a calculation in such a way that the actual prestress can deviate from the specified prestress. The calculation also takes into account other boundary conditions, such as the Poisson's ratio of the material.

You can easily check this if you vary the Poisson's ratio of the material. A Poisson's ratio other than 0 causes the deformation to interact in the x- and y-directions of the surface, which no longer results in a constant stress/strain over the entire surface.


If the Poisson's ratio is 0, you obtain the same results.


Keywords

Cable Membrane Initial prestress Modal analysis Initial strain

Write Comment...

Write Comment...

  • Views 337x
  • Updated 24 May 2022

Contact Us

Contact Dlubal

Unable to find the answer to your question? Contact us via phone, email, chat or forum or send us your question directly through our online form.

Submit Individual Question

+49 9673 9203 0

[email protected]

Analysis of Steel Joints \n Using FE Model in RFEM 6

Analysis of Steel Joints Using FE Model in RFEM 6

Webinar 29 September 2022 2:00 PM - 3:00 PM CEST

Online Training | English

RFEM 6 | Basics

Online Training 7 October 2022 9:00 AM - 1:00 PM CEST

Seismic Design According to EC 8 in RFEM 6 and RSTAB 9

Seismic Design According to Eurocode 8 in RFEM 6 and RSTAB 9

Webinar 11 October 2022 2:00 PM - 3:00 PM CEST

Online Training | English

RFEM 6 | Students | Introduction to Member Design

Online Training 12 October 2022 4:00 PM - 7:00 PM CEST

Online Training | English

Eurocode 2 | Concrete Structures According to DIN EN 1992-1-1

Online Training 18 October 2022 9:00 AM - 1:00 PM CEST

Online Training | English

RSECTION | Students | Introduction to Strength of Materials

Online Training 19 October 2022 4:00 PM - 7:00 PM CEST

Online Training | English

RFEM 6 | Students | Introduction to FEM

Online Training 27 October 2022 4:00 PM - 7:00 PM CEST

Online Training | English

RFEM 6 | Students | Introduction to Steel Design

Online Training 10 November 2022 4:00 PM - 5:00 PM CET

Online Training | English

Eurocode 3 | Steel Structures According to DIN EN 1993-1-1

Online Training 17 November 2022 9:00 AM - 1:00 PM CET

Online Training | English

RFEM 6 | Dynamic Analysis and Seismic Design According to EC 8

Online Training 23 November 2022 9:00 AM - 1:00 PM CET

Online Training | English

RFEM 6 | Students | Introduction to Timber Design

Online Training 25 November 2022 4:00 PM - 5:00 PM CET

Online Training | English

Eurocode 5 | Timber Structures According to DIN EN 1995-1-1

Online Training 8 December 2022 9:00 AM - 1:00 PM CET

Online Training | English

RFEM 6 | Dynamic Analysis and Seismic Design According to EC 8

Online Training 21 September 2022 9:00 AM - 1:00 PM CEST

Rhino/Grasshopper Integration in RFEM 6

Rhino/Grasshopper Integration in RFEM 6

Webinar 20 September 2022 2:00 PM - 3:00 PM EDT

Design Aluminum Structures \n in RFEM 6 and RSTAB 9

Model and Design Aluminum Structures in RFEM 6 and RSTAB 9

Webinar 15 September 2022 2:00 PM - 3:00 PM CEST

Online Training | English

Eurocode 5 | Timber Structures According to DIN EN 1995-1-1

Online Training 15 September 2022 9:00 AM - 1:00 PM CEST

Consider Construction Stages \n in RFEM 6

Consider Construction Stages in RFEM 6

Webinar 8 September 2022 2:00 PM - 3:00 PM CEST

Online Training | English

Eurocode 3 | Steel Structures According to DIN EN 1993-1-1

Online Training 8 September 2022 9:00 AM - 1:00 PM CEST