Prof. Bassem O. Andrawes Profile

Prof. Bassem O. Andrawes

Assistant Professor at Univ of Illinois

SPIE Involvement:

Author

Publications (3)

This will count as one of your downloads.

You will have access to both the presentation and article (if available).

DOWNLOAD NOW

This content is available for download via your institution's subscription. To access this item, please sign in to your personal account.

Email or Username Forgot your username?

Password Forgot your password?

Show

Keep me signed in

No SPIE account? Create an account

Proceedings Article | 18 April 2008 Paper

Seismic retrofitting of bridge columns using shape memory alloys

Bassem Andrawes, Moochul Shin

Proceedings Volume 6928, 69281K (2008) https://doi.org/10.1117/12.775480

KEYWORDS: Shape memory alloys, Bridges, Earthquakes, Motion models, Fiber reinforced polymers, Carbon, Motion analysis, Civil engineering, Smart structures, System integration

Read Abstract +

This analytical work focuses on enhancing the ductility capacity and damage mitigation of reinforced concrete bridge columns during earthquakes by using innovative active confinement technique. The high recovery stress associated with the shape recovery of shape memory alloys (SMAs) is exploited to apply the confining pressure. A 2-D analytical model for a single column is developed and analyzed. The model is used to evaluate the seismic behavior of the column retrofitted with SMA rings and compare it with the behavior of the column retrofitted with the more conventional approach using carbon fiber reinforced polymer (CFRP) sheets. The stress-strain behavior of the concrete confined with internal ties only, internal ties and external SMA rings, and internal ties and external CFRP sheets is described based on two different constitutive models. The column model is subjected to cyclic loading with increasing amplitude and a ground motion excitation. The analysis shows that the SMA rings provide the column with more damage protection represented by a reduction in the maximum strain by up to 273% compared to CFRP sheets. In addition, the column retrofitted with SMA rings shows smaller lateral drifts compared to the column retrofitted with the CFRP sheets when subjected to the same ground motion excitation. The superior performance of the SMA rings is primarily attributed to the increase in the compressive strength at early stages of loading associated with applying the active confinement pressure.

Proceedings Article | 17 May 2005 Paper

Effect of ambient temperature on the performance of shape memory alloy seismic devices

Bassem Andrawes, Reginald DesRoches

Proceedings Volume 5764, (2005) https://doi.org/10.1117/12.600006

KEYWORDS: Shape memory alloys, Bridges, Earthquakes, Motion models, Temperature metrology, Civil engineering, Buildings, Crystals, Thermal modeling, Thermal effects

Read Abstract +

Shape memory alloys (SMAs) are a class of metallic alloys that exhibit unique characteristics such as shape memory effect and superelasticity effect. SMAs are found in two main phases: the high temperature phase, which is known as austenite (superelastic), and the low temperature phase, which is known as martensite. Although there are few civil engineering applications using SMAs, there have been considerably large numbers of research studies focusing on exploiting SMAs in seismic resistant design and retrofit of buildings and bridges. Most of these studies focus on utilizing the superelasticity phenomenon exhibited by SMAs at high temperatures. The effect of ambient temperature variation on the efficacy of superelastic SMA devices that are used in seismic applications is a major concern. This paper presents an analytical investigation on the effect of ambient temperature variation on the performance of superelastic SMA bridge restrainers during earthquakes. A thermomechanical constitutive model is developed to describe the constitutive behavior of the SMA restrainers at various temperatures. The SMA model is implemented in a 2-DOF bridge model and tested using 20 historical ground motion records. The ambient temperature is varied from a temperature below A_f to a relatively high temperature. The results of the study showed that SMAs are more effective when used in its austenitic phase and thus when the temperature decreases below A_f SMA devices lose a major part of their efficiency. On the other hand, the study also showed that at high temperatures the ductility demand of the bridge frames increases.

Proceedings Article | 26 July 2004 Paper

Effect of cyclic modeling parameters on the behavior of shape memory alloys for seismic applications

Bassem Andrawes, Jason McCormick, Reginald DesRoches

Proceedings Volume 5390, (2004) https://doi.org/10.1117/12.542540

KEYWORDS: Shape memory alloys, Motion models, Bridges, Systems modeling, Earthquakes, Crystals, Data modeling, Civil engineering, Instrument modeling

Read Abstract +

The cyclic behavior of shape memory alloys (SMAs) in their austenitic form is studied to determine the most appropriate method of modeling in terms of both accuracy and ease of implementation. Four different models for SMA behavior are evaluated: (a) a simple nonlinear elastic model, (b) a trigger-line model, (c) a one-dimensional thermomechanical model, and (d) a one-dimensional thermomechanical model which accounts for the behavior of SMAs under cyclic loading. Using a two degree-of-freedom bridge model with SMA restrainers and a single degree-of-freedom building model with SMA cross-braces, the effect of using the different models on the seismic response of the bridge and building is evaluated. Using a suite of nine earthquake ground motions, the displacement response histories with the four different models are compared. The results illustrate that although the models show quite different behaviors for the SMAs, the resulting responses of the bridge and building are insensitive to the type of model used. For most of the ground motion records used, the difference in the maximum displacement for the four models was less than 15%. This study lends support to the use of more simplified models when evaluating the effectiveness of the SMAs for seismic response modification.

My Library

You currently do not have any folders to save your paper to! Create a new folder below.

Folder Name

Folder Description

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks. You are receiving this notice because your organization may not have SPIE eBooks access.*

*Shibboleth/Open Athens users─please sign in to access your institution's subscriptions.

To obtain this item, you may purchase the complete book in print or electronic format on SPIE.org.

ORGANIZATIONAL
Sign in with credentials provided by your organization.

Organizational Username

Organizational Password

Show/Hide Password

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members:

Non-members: ADD TO CART

Keywords/Phrases

Search In:

Publication Years