Evolving Methods in Creep Analysis

Oct 18, 2023
1 minute read
BLOG BRIDGE INSIGHT

Creep Analysis 2 

This blog article is related to the recent post of Creep Analysis 1. Feel free to access the previous article via this link: Creep Analysis 1. The same problem can be solved more elegantly, as shown in the same paper by Dr. El-Badry.

The stiffness equation between time t1 and t2 is

The stiffness equation between time t1 and t2

Here, the displacement changes which would occur between time t1 and t2 without any support changes are

 

displacement changes which would occur between time t1 and t2 without any support changes

The stiffness equation at time t0 is

 

The stiffness equation at time t0

Substitute Eq(5) into Eq(2)

 

Substitute Eq(5) into Eq(2)

Substitute Eq(6) into Eq(1)

 

Substitute Eq(6) into Eq(1)

Here

 

stiffness matrix

 

Substitute Eq(8) into Eq(7)

 

Substitute Eq(8) into Eq(7)

 

We know the fixed end force changes between time t1 and t2, and we can calculate the reaction changes between the same time intervals. Not all commercial programs can handle these fixed end forces, but we can convert fixed end forces into nodal loads and do the post-processing easily.

This method is more elegant and faster than the previous method and very helpful to understand the concept of creep analysis. However, the computational quantity is no longer a problem with modern 32-bit computers. The author believes the previous method is also a good one to implement with computers once the reader fully understands this method.

 

About the Editor
Seungwoo Lee, Ph.D., P.E., S.E.
Senior Supervising Engineer at WSP USAs (Tampa, FL)

He is a Senior Supervising Engineer with a high level of expertise in the design and analysis of suspension bridges. He has a solid fundamental understanding of structures and can apply his knowledge exceptionally well to the design and analysis of highly complex structures. He is also a strong communicator, able to identify and distill the key information that is relevant to the task at hand and present it in a clear and quickly understandable manner.

Subscribe MOTIVE Newsletter

Comments
Keep exploring engineering ideas