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Allan Manalo - One of the best experts on this subject based on the ideXlab platform.

  • effect of Bolt threads on the double lap joint strength of pultruded fibre reinforced polymer composite materials
    Construction and Building Materials, 2018
    Co-Authors: R M Hizam, Allan Manalo
    Abstract:

    Abstract The ability to provide effective and adaptable joints for pultruded fibre reinforced polymer (PFRP) is crucial for its widespread application in civil infrastructure. This experimental based study on 150 double lap joints specimens investigated the effects of Threaded Bolt and clamping pressure on the joint strength behaviour, failure mechanisms and joint efficiency of Bolted joints in PFRP. Double lap joints in both longitudinal and transverse directions of the laminates and with different edge distance-to-Bolt diameter (e/db) were prepared and tested in accordance with ASTM D5961 standards. The joint strength in the longitudinal laminates with plain Bolt increased for e/db ratio for up to 4 and with no appreciable strength gain after exceeding this ratio. On the other hand, about 30%–40% reduction in joint strength was observed in the longitudinal direction due to the Bolt thread tearing through the laminates. This leads to a recommendation of 0.6 reduction factor in preliminary design of PFRP Bolted connections with Bolt thread present. Meanwhile, only a marginal difference of 7% was observed in transverse direction. Furthermore, the introduction of lateral clamping pressure had increased the joint strength by 60%–90% and this has lessened the thread casualty effect on the pultruded composite joints.

  • an experimental investigation on the effect of Threaded Bolt on the double lap joint strength of pultruded fibre reinforced polymer
    2014
    Co-Authors: R M Hizam, Allan Manalo
    Abstract:

    The ability to provide the joint versatility for pultruded fibre reinforced polymer (PFRP) in civil structures industry is crucial for its application demands. Bolted joint is extensively used in the industry due to low cost and ease of assembly. However, this jointing method can compromise the PFRP strength at the joint due to poor quality of drilling techniques, accuracy of hole size and Threaded Bolt. In this study, the main objective is to investigate the effect of Threaded Bolt on the strength of Bolted joints in pultruded fibre reinforced polymer. Double lap joint configuration was used on both longitudinal and transverse laminates and tested to failure (in tension) in accordance with ASTM D5961. The test specimens failed in shear-out (heavily crushed) mode and net-tension mode for longitudinal and transverse laminates, respectively. A significant joint capacity reduction was observed on the Threaded samples due to unevenness of the contact surface. The load-displacement curve shows the slope with several knees after the first drop, which may indicate some damping effects and unstable development of internal damage.

R M Hizam - One of the best experts on this subject based on the ideXlab platform.

  • effect of Bolt threads on the double lap joint strength of pultruded fibre reinforced polymer composite materials
    Construction and Building Materials, 2018
    Co-Authors: R M Hizam, Allan Manalo
    Abstract:

    Abstract The ability to provide effective and adaptable joints for pultruded fibre reinforced polymer (PFRP) is crucial for its widespread application in civil infrastructure. This experimental based study on 150 double lap joints specimens investigated the effects of Threaded Bolt and clamping pressure on the joint strength behaviour, failure mechanisms and joint efficiency of Bolted joints in PFRP. Double lap joints in both longitudinal and transverse directions of the laminates and with different edge distance-to-Bolt diameter (e/db) were prepared and tested in accordance with ASTM D5961 standards. The joint strength in the longitudinal laminates with plain Bolt increased for e/db ratio for up to 4 and with no appreciable strength gain after exceeding this ratio. On the other hand, about 30%–40% reduction in joint strength was observed in the longitudinal direction due to the Bolt thread tearing through the laminates. This leads to a recommendation of 0.6 reduction factor in preliminary design of PFRP Bolted connections with Bolt thread present. Meanwhile, only a marginal difference of 7% was observed in transverse direction. Furthermore, the introduction of lateral clamping pressure had increased the joint strength by 60%–90% and this has lessened the thread casualty effect on the pultruded composite joints.

  • an experimental investigation on the effect of Threaded Bolt on the double lap joint strength of pultruded fibre reinforced polymer
    2014
    Co-Authors: R M Hizam, Allan Manalo
    Abstract:

    The ability to provide the joint versatility for pultruded fibre reinforced polymer (PFRP) in civil structures industry is crucial for its application demands. Bolted joint is extensively used in the industry due to low cost and ease of assembly. However, this jointing method can compromise the PFRP strength at the joint due to poor quality of drilling techniques, accuracy of hole size and Threaded Bolt. In this study, the main objective is to investigate the effect of Threaded Bolt on the strength of Bolted joints in pultruded fibre reinforced polymer. Double lap joint configuration was used on both longitudinal and transverse laminates and tested to failure (in tension) in accordance with ASTM D5961. The test specimens failed in shear-out (heavily crushed) mode and net-tension mode for longitudinal and transverse laminates, respectively. A significant joint capacity reduction was observed on the Threaded samples due to unevenness of the contact surface. The load-displacement curve shows the slope with several knees after the first drop, which may indicate some damping effects and unstable development of internal damage.

Kuhn Joachim - One of the best experts on this subject based on the ideXlab platform.

Yu Bai - One of the best experts on this subject based on the ideXlab platform.

  • Joint strength of single-Bolted pultruded GFRP square hollow sections with mechanical inserts under elevated temperatures
    'American Society of Civil Engineers (ASCE)', 2020
    Co-Authors: Hizam R. M., Manalo, Allan C., Karunasena Warna, Yu Bai
    Abstract:

    The sensitivity of the joint performance of pultruded fiber reinforced polymer (FRP) to elevated temperatures has been known to limit the widespread application of FRP composites in civil construction. This paper presents a study of the effect of elevated temperatures and mechanical inserts on the joint strength and failure mechanism of a square hollow section (SHS) of pultruded glass FRP (GFRP) composites. Three pultruded GFRP Bolted joint configurations were implemented—namely, a joint without mechanical insert (N), a joint with mechanical insert with tight-fit attachment (I), and a joint with mechanical insert bonded with epoxy adhesive (G). Sixty (60) square pultruded GFRPs with a single all-Threaded Bolt connection each were tested up to failure at room temperature 40°C, 60°C, and 80°C. Specimen G exhibited the highest joint strength, with twice more than that of Specimen N across the temperature range. Specimens N and I failed by shear-out at high temperatures mainly due to the deterioration of the interfacial bond between the fibers and the matrix. The strength reduction factor, k, and modification factor, m, which incorporate the increasing temperatures and the designed joint configurations showed excellent agreement when compared to the experimental results

Rusmi, Mohammad Hizam Shah - One of the best experts on this subject based on the ideXlab platform.

  • Behaviour of Bolted connection system in pultruded GFRP structures
    2018
    Co-Authors: Rusmi, Mohammad Hizam Shah
    Abstract:

    The pultruded GFRP hollow sections, in particular, have received growing interest from the engineering community due to better torsional rigidity, effective resistance of out-of-plane forces, high load transfer and improved strength and stiffness of the minor axis. However, one of the significant issues that hinders the widespread use of pultruded GFRP hollow sections is the inadequacy or unpredictability of its connection system. In this study, the behaviour of pultruded GFRP truss structure using through-Bolt connection system was investigated based on the current industrial practice in Australia. The through-Bolt connection system is incorporated with an FRP mechanical insert as a filled-type connection element and currently, there is no scientific research focusing on joint behaviour of pultruded GFRP hollow profiles with mechanical inserts. This has been the key motivation for this research whereby the suitability and joint strength adequacy of Bolted connection with insert for pultruded FRP, in particular, tubular profiles were examined. Therefore, the study ultimately investigated this particular jointing technique on pultruded GFRP trusses and aimed to understand how the loads are resisted, transferred, and distributed to each FRP component. The experimental data and theoretical predictions developed in this study are critical to produce a safe, reliable and adequate connection system for pultruded GFRP hollow sections. This thesis is presented as a compilation of technical papers. In the first paper, effects of Threaded Bolt with varying end distance to Bolt diameter, laminate thickness, clamping pressure and laminate orientations (longitudinal and transverse) on the joint strength behaviour, joint efficiency and mode of failure were evaluated using a double lap joint test set-up configuration. The test results obtained from the effects of using Threaded Bolt were compared to that of plain Bolt in order to assess the differences in joint behaviour and possible reduction in joint capacity. In this experiment, the joint was designed to promote bearing failure as it is preferable in composite joint due to its progressive nature of failure. From this study, approximately 30-40% reduction in joint strength was observed for specimens with longitudinal laminate orientation caused by laminate tearing of the Bolt. In addition, under scanning electron microscope (SEM) imaging, this damaging effect was further observed to better understand its mechanism and how it affects the resulting mode of failures. In the second paper, the joint behaviour of pultruded GFRP hollow sections with a single all-Threaded Bolt and mechanical insert connection system was investigated under elevated in-service temperature. A comparison of different Bolted joint configurations of pultruded GFRP hollow sections, namely joint without mechanical insert (N), joint with mechanical insert with tight-fit attachment (I) and joint with mechanical insert bonded with epoxy adhesive (G) was conducted and the effects on the joint strength and failure mechanism were evaluated. The results of this experimental work have demonstrated that the Bolted joint with adhesively bonded mechanical insert sustained the highest load-carrying capacity across the elevated temperatures compared to other configurations. Also, the proposed joint strength prediction equation, which incorporates the strength reduction and modification factors based on different joint configurations involving mechanical insert, produced reasonable outcomes against experimental failure load. These results suggest that, the use of mechanical inserts to strengthen Bolted connections system can be adopted in pultruded GFRP hollow sections and the joint performance of this configuration at a structural level was discussed in the next paper. In the third paper, the joint behaviour of through-Bolt connection with mechanical insert under eccentric loading was investigated. The joint configuration was adopted in pultruded GFRP T-joints using both single and double bottom chords, with the former imbalanced configuration intended to impart load eccentricity. This eccentric condition can be found in composite truss bridges. The experimental results showed that, the presence of mechanical inserts in both single and double bottom chords of the T-joints had improved the joint strength and fixture stiffness when compared to their insert-less counterparts. It was found that the mechanical insert has prevented Bolt flexure and contributed to the improvement in bending resistance when subjected to a couple moment developed due to eccentricity. In the last paper, the structural behaviour of double-chorded pultruded GFRP trusses connected using through-Bolt with mechanical inserts under different load cases were investigated. The structural performance of the trusses was described in terms of load-midspan deflection response, force distribution of internal members and mode of failure. The results of this study indicate that the adopted through-Bolt with mechanical insert connection system possess high joint load-carrying capacity and demonstrated effective transmissitheoretical strength limits of pultruded GFRP truss members in tension, compression and flexural according to ASCE pre-standard were in close agreement with the experimental results. Meanwhile, the prediction equation proposed in the second paper was used here to evaluate the joint load-carrying capacity of the pultruded GFRP trusses. A two-dimensional numerical model to simulate the behaviour of the pultruded GFRP trusses was constructed using Strand7 finite element analysis software. Satisfactory comparisons against experimental results were achieved and this demonstrates the validity of the Strand7 simplified numerical model. From this overall research program, it can be concluded that the combination of through-Bolt and mechanical insert is a promising connection system for pultruded GFRP in truss application. The proposed factors and theoretical joint strength equations developed in this research can be important tools for practitioners to perform strength analysis of through-Bolt with mechanical insert connection system, encouraging its acceptance and utilisation, especially in truss application.on of internal forces to other truss members. Th