An optimal Plastic Stringer Model Solution

Use the optimal plastic stringer model solution to design shear walls, concrete diaphragms etc.

stringer model of concrete diaphragm
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A Powerful Stringer Model!

Concrete Diaphragm

Moddeling of concrete diaphragms as stringer models is one of the primary uses for PolyStringer.

Optimal Plastic Solution

PolyStringer determines the optimal plastic solution, which minimizes the required reinforcement. This solution is very true to the actual behavior of reinforced concrete.

Shear Wall

Utilize the full capacity of shear walls with door- or window openings with a PolyStringer stringer model.


Using the PolyStringer API plugin it is possible to automate your stringer model calculations through Excel. Read more or contact us to get started.

What is a Stringer Model, and why use it?

Stringer models are ideal for modeling reinforced concrete structures mainly exposed to in-plane forces such as diaphragms and shear walls in pre-cast concrete structures.

Reinforced concrete is a plastic material which behaves far from elastic as we know from other materials such as steel etc. Therefore, finite element models aren’t ideal for design of reinforced concrete structures, and design by finite element models often lead to far more reinforcement than necessary.

Due to minor tensile cracks in the concrete the internal forces will automatically redistribute to where extra capacity is available and lead to increased capacity. The optimal plastic solution, which is the solution with the least required reinforcement is therefore an ideal solution for reinforced concrete. Furthermore, it has been shown that this solution is very true to the actual behavior of reinforced concrete and yields very accurate results with respect to SLS.

Stringer models for non-ridged diaphragms

In the case of a diaphragm with a large cantilevered part, or significant holes. The diaphragm cannot be considered ridged. In this case PolyStringer can be used to determine the reactions in the supporting shear walls based on the distribution that is most gentle to the diaphragm. An example of this can be seen in the pictures to the right.

Want to know more?

PolyStringer Full logo

To learn more about PolyStringer go to the official website. Here you will find more information, videos etc.


To learn more about other products from PolyStruc, check out PolyBeam – a Simple, yet powerful beam calculator.