Analysis and behavior of high-strength rectangular CFT columns

Abstract

The current AISC Specification (AISC 360-16) specifies the material strength limits for concrete-filled steel tube (CFT) columns. According to AISC 360-16, the steel yield stress (F y ) for CFT columns should not exceed 525 MPa, and the concrete compressive strength (f' c ) should not exceed 70 MPa. CFT columns are classified as high strength if either F y or f' c exceeds these specified limits, and are classified as conventional strength if both F y and f' c are less than or equal to the limits. Due to lack of adequate research and comprehensive design equations, AISC 360-16 does not endorse the use of high-strength materials for CFT columns. This paper makes a contribution towards addressing this gap using a two-step approach. The first step consists of compiling an experimental database of high-strength rectangular CFT column tests in the literature and evaluating the possibility of extending the current AISC 360-16 design equations to high-strength rectangular CFT columns. The second step consists of developing and benchmarking detailed 3D nonlinear finite element models for predicting the behavior of high-strength CFT columns from the database. The benchmarked models are being used to perform comprehensive parametric studies to address gaps in the database and propose design equations for high-strength rectangular CFT members, which will be part of a future paper.

Universelle Hochleistungsstützen aus hochfesten Stählen ohne Schweißen

“…Untersuchungen von Druckgliedern mit höheren Festigkeiten werden erst seit Kurzem aufgenommen. Sie beschränken sich jedoch entweder auf die Untersuchung reiner Stahlstützen [6, 7] oder gedrungener höchstfester Verbundstützen ohne Stabilitätsgefährdung [8–10]. Ausbetonierte Rundhohlprofil‐Verbundstützen mit massivem Kern wurden bisher nur für Stahlgüten bis S460 in [11, 12] untersucht.…”

Experimental investigations on composite columns: round hollow sections with embedded solid core section made of high‐strength steel

“…However, the normative rules of composite columns according to Eurocode 4 [1] are a central problem, as they only consider steels up to S460, which represents the state of the art from the 1980s to the 1990s. Investigations of high-strength members have only recently been undertaken, but they are limited to either the examination of pure steel columns [2] [3] or stubby high-strength composite columns without stability problems [4] [5]. Round hollow sections with embedded solid core section have only been examined for steel grades up to S460 [6] [7].…”