---
type: concept
title: "Midas Civil Nonlinear Time History and Hysteresis Models"
created: 2026-06-02
updated: 2026-06-02
address: c-000166
aliases:
  - MIDAS Civil nonlinear time history
  - midas Civil hysteresis models
tags:
  - concept
  - finite-element-method
  - midas-civil
  - dynamics
  - nonlinear-analysis
status: current
related:
  - "[[Midas-Civil-Analysis-Reference|Midas Civil Analysis Reference]]"
  - "[[midas Civil]]"
  - "[[Direct Time Integration Methods]]"
  - "[[Transient Dynamic Elasto-Plastic Analysis]]"
  - "[[Abaqus Metal Plasticity Models]]"
sources:
  - "[[Midas-Civil-Analysis-Reference|Midas Civil Analysis Reference]]"
---

# Midas Civil Nonlinear Time History and Hysteresis Models

## Definition

Midas Civil nonlinear time history and hysteresis models are the direct dynamic analysis procedures and inelastic component laws used when member, link, truss, or fiber behavior changes during a time-dependent load history.

## How It Works

The manual describes nonlinear equations of motion, nonlinear static initialization, initial section-force consideration, initial stiffness options, and Newton-Raphson iteration with or without convergence calculation. Inelastic components include inelastic beams, inelastic General Links, and inelastic trusses.

Hysteresis options include bilinear, trilinear, tetralinear, origin-oriented, peak-oriented, Clough, Takeda-family, slip, Ramberg-Osgood, and Hardin-Drnevich models. Multi-axial hinge models include kinematic hardening and P-M or P-M-M interaction. Fiber models include steel and concrete constitutive models for section response.

## Solver Development Notes

- Time integration, nonlinear iteration, and hysteresis state update must share one accepted-state timeline.
- Hysteresis laws need explicit unloading/reloading rules; a yield surface alone is not enough.
- Multi-axial hinge interaction requires robust section-force mapping and yield-surface projection.
- Fiber sections require material-point state management inside a member-level element.

## Connections

- [[Direct Time Integration Methods]] gives the transient integration base.
- [[Transient Dynamic Elasto-Plastic Analysis]] connects inertia and plasticity.
- [[Abaqus Metal Plasticity Models]] and [[Abaqus Geomaterial and Concrete Plasticity]] provide constitutive comparison points.