Numerical Investigation on Hollow Pultruded Fibre Reinforced Polymer Tube Columns

As the axial behaviour of hollow pultruded fibre reinforced polymer (PFRP) profiles is governed by the instability conditions due to the local and global buckling, the determination of the safe load carrying capacity of FRP columns is vital. The compressive performance of PFRP tube depends on many factors such as fibre type, fibre content, and orientation of fibre layers, cross-section, thickness and height of the column member. In this study, concentric compressive testing was conducted using PFRP short columns. Based on the fibre orientation and thickness, the samples were divided into two groups of tubes in a square shape and two groups in a circular shape. The height of columns is designed to keep the slenderness ratio (length/lateral dimension) of 5. The axial behaviour of FRP columns was simulated using STRAND7 finite element software package. The laminate method was followed to define the mechanical properties of the FRP material. Failure was investigated by using the Tsai-Wu failure criterion. The experimental results show that the failure mode of the hollow square tube was either local buckling or corner splitting at the mid-height followed by buckling. Although both types of circular tubes failed in a similar way by crushing one end with high noise, followed by separation of the crushed end into strips, the stiffness and the load capacity of PFRP column was higher for the profiles with fibres oriented close to the axial direction. The numerical results are in close agreement with the peak value of the experimental results. This can be extended to study the effects of all factors that influence the axial behaviour of PFRP columns numerically

The Ultrasonic Measurement of Elastic Constants of Structural FRP Composites

Interest in fiber reinforced polymeric (FRP) composites for structural highway applications has generated the need for reliable techniques which may be used to measure all of the elastic constants of these materials. Mechanical techniques may only be used to measure some of the engineering constants of these anisotropic materials due to the geometry of the pultruded members. Further, mechanical tests are destructive in nature. Ultrasonic techniques are uniquely qualified for the nondestructive measurement of all of the elastic constants of these materials. This paper presents the results of three ultrasonic techniques. The first of these is an immersion technique, similar to that presented by Gieske and Allred [1]. The last two techniques were developed specifically for this research, and implement optical generation and detection of surface acoustic waves for the measurement of some of the elastic constants. The results of the various techniques are compared to each other, as well as to results from mechanical tests.</p

Comprehensive evaluation of candidate guardrail delineation systems

Issued as final reportGeorgia Department of Transportatio

A Case-Based Decision Support System for Land Development Control

Interest in fiber reinforced polymeric (FRP) composites for structural highway applications has generated the need for reliable techniques which may be used to measure all of the elastic constants of these materials. Mechanical techniques may only be used to measure some of the engineering constants of these anisotropic materials due to the geometry of the pultruded members. Further, mechanical tests are destructive in nature. Ultrasonic techniques are uniquely qualified for the nondestructive measurement of all of the elastic constants of these materials. This paper presents the results of three ultrasonic techniques. The first of these is an immersion technique, similar to that presented by Gieske and Allred [1]. The last two techniques were developed specifically for this research, and implement optical generation and detection of surface acoustic waves for the measurement of some of the elastic constants. The results of the various techniques are compared to each other, as well as to results from mechanical tests