Stability and crushing behaviors of cylindrical tubes with a cutout, including the mitigation of their local instability using shape memory alloys.
Date
2006
Authors
Han, Haipeng.
Journal Title
Journal ISSN
Volume Title
Publisher
Dalhousie University
Abstract
Description
Cylindrical tubes are commonly used in engineering structures. During their service life, these components are often subjected to axial compressive loading, either statically or dynamically. It is known that the presence of a cutout can lead to substantial stress concentrations in the structure. Nevertheless, there is still a lack of understanding of how a cutout would influence such components' stability and crushing behaviors.
The influence of a cutout on the load-bearing capacity and buckling behavior of aluminum cylindrical shell was studied in the first stage of this thesis. Several parameters that could influence the stability behavior of cylindrical shells, including diameter/thickness (D/t) ratio, length/diameter (L/D) ratio, as well as the cutout's size and location were considered in this study. Through verification of the computational results with an experimental investigation, empirical equations predicting the "buckling load reduction factor" were developed.
The quasi-static and dynamic crushing behaviors and energy absorption capacity of aluminum and steel tubes with a cutout were studied numerically and experimentally. Various L/D ratios of the tubes and different cutout locations along the tubes were considered. A range of impact velocities, from zero up to 20m/s, equivalent to an intermediate speed car crash, were analyzed. Subsequently, the correlation between the material properties, loading speed, cutout location and crushing behavior of the tubes was established. Based on the outcome of this numerical and experimental investigation, a set of empirical equations for predicting the mean crushing force of the tubes having a cutout was developed.
A hybrid of pultruded and braided composite tubes was proposed as a superior effective energy absorber to pultruded tubes. The crushing behavior and energy absorption capacity of this proposed new energy absorber were characterized through numerical and experiment investigations.
A feasibility study was carried out to study the mitigation of local instability in a composite cylindrical shell using shape memory alloy (SMA) materials. The outcome of this preliminary work showed that it is very promising to use SMA in mitigating the local instability of plates/shells. Significant factors influencing the use of SMA in this application were investigated.
Thesis (Ph.D.)--Dalhousie University (Canada), 2006.
The influence of a cutout on the load-bearing capacity and buckling behavior of aluminum cylindrical shell was studied in the first stage of this thesis. Several parameters that could influence the stability behavior of cylindrical shells, including diameter/thickness (D/t) ratio, length/diameter (L/D) ratio, as well as the cutout's size and location were considered in this study. Through verification of the computational results with an experimental investigation, empirical equations predicting the "buckling load reduction factor" were developed.
The quasi-static and dynamic crushing behaviors and energy absorption capacity of aluminum and steel tubes with a cutout were studied numerically and experimentally. Various L/D ratios of the tubes and different cutout locations along the tubes were considered. A range of impact velocities, from zero up to 20m/s, equivalent to an intermediate speed car crash, were analyzed. Subsequently, the correlation between the material properties, loading speed, cutout location and crushing behavior of the tubes was established. Based on the outcome of this numerical and experimental investigation, a set of empirical equations for predicting the mean crushing force of the tubes having a cutout was developed.
A hybrid of pultruded and braided composite tubes was proposed as a superior effective energy absorber to pultruded tubes. The crushing behavior and energy absorption capacity of this proposed new energy absorber were characterized through numerical and experiment investigations.
A feasibility study was carried out to study the mitigation of local instability in a composite cylindrical shell using shape memory alloy (SMA) materials. The outcome of this preliminary work showed that it is very promising to use SMA in mitigating the local instability of plates/shells. Significant factors influencing the use of SMA in this application were investigated.
Thesis (Ph.D.)--Dalhousie University (Canada), 2006.
Keywords
Engineering, Civil.