Nonlinear Dynamic Analysis of Progressive Collapse in Steel Tube Concrete Frame-Core Tube Hybrid Structures

Literature Overview

The paper by Wei Guoqiang, Zheng Long, Wang Wenda, and Song Zilong from Lanzhou University of Technology and Tianshui Normal University (2019), funded by the National Natural Science Foundation of China (51268038), the Gansu Science and Technology Support Program (1604FKCA107), and the Gansu Higher Education Research Project (2018A-079), presents nonlinear dynamic analysis of progressive collapse in a 33-story steel tube concrete (SRC) frame-core tube hybrid structure. Published in the Journal of Seismological Engineering (Vol. 41, No. 3, pp. 581-587), this study employs ABAQUS with fiber beam elements and layered shell elements, utilizing a custom material constitutive subroutine (iFiberLUT).

Core Technical Content

The study investigates the progressive collapse mechanism of a 33-story SRC frame-core tube hybrid structure under local member failure scenarios. The analysis considers column failures at floors 1, 17, and 33, as well as core tube wall failures at the same levels.

Analysis Methodology

Analysis Parameter	Specification
Software	ABAQUS
Structural model	33-story SRC frame-core tube hybrid
Element types	Fiber beam elements (columns/beams) + Layered shell elements (core walls)
Material model	Custom subroutine iFiberLUT (fiber-based constitutive model)
Failure scenarios	Column failure at floors 1, 17, 33; Core wall failure at floors 1, 17, 33
Analysis type	Nonlinear dynamic (time-history)
Key response metrics	Vertical displacement, displacement oscillation, load redistribution

Key Findings and Analysis

Displacement Response by Failure Location

Failure Location	Maximum Vertical Displacement	Oscillation Amplitude	Relative Severity
Floor 33 (top)	Largest	Most pronounced	Most severe
Floor 17 (mid)	Moderate	Moderate	Moderate
Floor 1 (base)	Smallest	Least pronounced	Least severe

The finding that top-floor failures produce the largest displacement response is counterintuitive but physically explainable: when a top-floor member fails, the entire structure above the failure point (including the failed member's own mass) must be supported by the remaining structure below. The dynamic amplification is greatest because the inertia forces from the upper mass are not restrained by any upper structure.

Column Failure vs. Core Wall Failure

Comparison	Column Failure	Core Wall Failure
Vertical displacement	Larger	Smaller
Oscillation	More pronounced	Less pronounced
Core tube effect	Minimal	Minimal
Membrane effect	Enhanced by core tube	Enhanced by core tube