> For the complete documentation index, see [llms.txt](https://tlcfem.gitbook.io/suanpan-manual/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://tlcfem.gitbook.io/suanpan-manual/material/material1d/hysteresis/bilinearpo.md).

# BilinearPO

Bilinear Peak Oriented Model

## Syntax

For symmetric response between compression and tension,

```
material BilinearPO (1) (2) (3) (4) [5]
# (1) int, unique material tag
# (2) double, elastic modulus
# (3) double, yield strain
# (4) double, hardening ratio
# [5] double, density, default: 0.0
```

For asymmetric response,

```
material BilinearPO (1) (2) (3) (4) (5) (6) [7]
# (1) int, unique material tag
# (2) double, elastic modulus
# (3) double, tension yield strain
# (4) double, tension hardening ratio
# (5) double, compression yield strain
# (6) double, compression hardening ratio
# [7] double, density, default: 0.0
```

## History Variable Layout

Since it is derived from the [`SimpleHysteresis`](/suanpan-manual/material/material1d/hysteresis/simplehysteresis.md) model, they share the same history variable layout.

## Example

### Symmetric Response

```
material BilinearPO 1 2E4 1E-3 .02
materialTest1D 1 1E-4 50 100 150 200 250 300 150
```

![example one](https://1124082496-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FEquxr3H9WpPg4iPvT2mB%2Fuploads%2Fgit-blob-dccfce4c6144b97e6ca99ef473344129da6a7cca%2FBilinearPO.EX1.svg?alt=media)

### Asymmetric Response

```
material BilinearPO 1 2E4 1E-3 .02 2E-3 -.05
materialTest1D 1 1E-4 50 100 150 200 250 300 150
```

![example two](https://1124082496-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FEquxr3H9WpPg4iPvT2mB%2Fuploads%2Fgit-blob-068762a2d6f6ee53b1b39bdfe673de53ea212d98%2FBilinearPO.EX2.svg?alt=media)


---

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