Experimental research on shear performance of single bolt joints of bamboo curtain plywood

This paper focuses on the shear resistance of the bolted connection between steel plate and bamboo curtain plywood. From the fifteen groups of specimens, the performance grade, bolt diameter and end distance of bolts have an influence on the ultimate bearing capacity of joints and the yield load of joints and the yield load is 65%∼75% of the ultimate load. The initial stiffness of the node increases with the bolt diameter increasing. Provide certain materials and theoretical references for bamboo in the future design and research.

A MULTISCALE MODELING AND X-RAY CT EXPLORATION OF BEARING FAILURE MECHANISMS IN A COUNTERSUNK BOLTED COMPOSITE STRUCTURE

To investigate the failure mechanism in composite bolted joints, an in-situ X-Ray computed tomography (XCT) technique was developed and single shear bearing (SSB) tests were performed with quasi-isotropic layup. High-fidelity XCT was explored for the detection and characterization of bearing failure in bolted composite components without removing the fastener. A novel load frame was also introduced for in-situ XCT scan and a preliminary scan was performed. A micro-macro coupling modeling approach was proposed on the basis of continuum damage mechanics (CDM) method and a static bearing model, which was based on micromechanics analysis to consider the residual stress after fiber kinking and matrix cracking under compression in the bearing region. The SSB specimens were modified using a larger bolt diameter to avoid bolt failure and achieve extensive bearing failure. The developed modeling approach was verified using SSB test data by comparing the predicted load displacement response with experimental measurement and the failure patterns obtained from XCT scanning images.

Assessment of Rotational Stiffness for Metallic Hinged Base Plates under Axial Loads and Moments

Pinned base plate connections are the most common base connection used in low-rise steel buildings. In this research, an extensive parametric study is performed using the Finite Element (FE) software Abaqus to determine the elastic rotational stiffness, moment resistance, and energy absorption of the pinned base plate connection connected to a reinforced concrete footing and subjected to an eccentric axial load. The developed FE model is validated using experimental results from the literature. Moreover, an intensive parametric study is conducted to understand the behavior of these connections better. The investigated parameters include the base plate thickness, anchor bolt diameter, and arrangement and number of bolts. The most effective parameters that affect the elastic rotational stiffness and moment resistance of pinned base connections are the anchor bolt arrangement and diameter. The maximum increase in the rotational stiffness was 53% for the anchor bolt diameter of 30 mm when the base plate thickness increased from 12 mm to 30 mm. Based on the base plate thickness, the moment resistance is improved by 150–260% when the bolt diameter increases from 12 mm to 30 mm.

Parallel Glueline of Withdrawal Capacity for Mengkulang Glulam

The failure modes and load-carrying capacity of timber connection can be predicted using European Yield Model (EYM). In the load-carrying capacity formula, an unknown parameter for Mengkulang Glulam with the bolt as a fastener, is the withdrawal capacity, Fax,Rk (kN). In this research, the withdrawal capacity tests were conducted with respect to the difference in bolt diameter and glue line existences. The results showed the larger diameter 18 mm parallel with the glue line giving the highest withdrawal capacity and resistance when compared to the same diameter without glue line and 14 mm diameter with and without the glue line. Keywords: Engineered Wood Product (EWP); Structural Material; Withdrawal Capacity; European Yield Model (EYM) eISSN: 2398-4287© 2021. The Authors. Published for AMER ABRA cE-Bs by e-International Publishing House, Ltd., UK. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer–review under responsibility of AMER (Association of Malaysian Environment-Behaviour Researchers), ABRA (Association of Behavioural Researchers on Asians/Africans/Arabians) and cE-Bs (Centre for Environment-Behaviour Studies), Faculty of Architecture, Planning & Surveying, Universiti Teknologi MARA, Malaysia. DOI: https://doi.org/10.21834/ebpj.v6iSI4.3030

Investigation on the Seismic Performance of High-Strength Bolt-Rubber (HSBR) Connection in a Steel Frame

The existing buildings can be improved under the seismic effect by adding rubber to the bolts in the connection. The buildings when maintenance work is happening there is a problem many times and it should be evacuated and requires high cost. This study aims to maintain the building without having to remove it and at a very low cost compared to other methods. This study includes six models divided into two groups. The two groups differ in terms of the number of bolts in the contact area between the column and the beam in the steel frame. The first group models contain four bolts in the connection area and the second group forms contain five bolts in the contact area. Each group includes three models representing the first form of a reference model that has not rubber material around the bolts in the connection area, the second model contains 150% rubber than a bolt diameter around one bolt of the connection area, and all the bolts in the connection area in the third model are warped with rubber. The presence of rubber around one bolt gave a load, displacement, drifting, damping ratio, ductility index energy dissipation close to models where all contact bolts are warped with rubber material

Studi Eksperimental Kuat Tumpu Baut Sejajar Serat Metode Lubang Penuh dan Setengah Lubang

ABSTRAKKuat tumpu baut merupakan salah satu parameter penting dalam menentukan suatu sambungan baut. Berdasarkan persamaan SNI 7973:2013, kuat tumpu ditentukan berdasarkan berat jenis kayu, diameter pengencang, dan arah serat kayu. Pada penelitian kali ini terdapat dua metode pengujian eksperimental yaitu metode lubang penuh dan metode setengah lubang berdasarkan ASTM D5764-97a (2002). Pengujian dilakukan menggunakan kayu Mahoni dengan sejajar arah serat dan tiga variasi diameter baut yaitu 1/2 inchi, 5/8 inchi dan 3/4 inchi yang dibandingkan dengan analisis teoritis berdasarkan SNI 7973:2013. Hasil penelitian menunjukan bahwa pengujian eksperimental kuat tumpu baut memiliki nilai yang lebih besar dibandingkan dengan persamaan berdasarkan SNI 7973:2013, dengan nilai persen beda untuk pengujian metode lubang penuh sebesar 22,914% untuk sampel a; 5,806% untuk sampel b; 3,759% untuk sampel c; sedangkan untuk pengujian menggunakan metode setengah lubang sebesar 20,927% untuk sampel AA; 16,954% untuk sampel BB; 15,326% untuk sampel CC.Kata kunci: kuat tumpu baut, sejajar serat, SNI 7973:2013 ABSTRACTBolt bearing strength is one of the important parameters in bolt connetion design. According to the SNI 7973:2013, bearing strength is determined based on specific gravity of timber, diameter of fasterner and direction of timber grain. In this research, there are two experimental testing methods, full hole and half hole testing based on ASTM D5764-97a (2002). Mahogany timber with parallel grain direction was carried out in this test using three variations of bolt diameter, which are 1/2 in, 5/8 in and 3/4 in. This study compares the value of bolt bearing strength with theoritical analysis based on SNI 7973:2013. The result showed that the experimental of bearing strength had a greater value than the equation of theoritical analysis based on SNI 7973:2013, with percentage of difference for full hole testing are 22.914% for sample a, 5.806% for sample b, 3.759% for sample c, while the percentage of difference for half hole testing are 20,297% for sample AA, 16.954% for sample BB, and 15.326% for sample CC.Keywords: bolt bearing strength, parallel grain, SNI 7973:2013

Studying the performance of fully encapsulated rock bolts with modified structural elements

Numerical simulation is a useful tool in investigating the loading performance of rock bolts. The cable structural elements (cableSELs) in FLAC3D are commonly adopted to simulate rock bolts to solve geotechnical issues. In this study, the bonding performance of the interface between the rock bolt and the grout material was simulated with a two-stage shearing coupling model. Furthermore, the FISH language was used to incorporate this two-stage shear coupling model into FLAC3D to modify the current cableSELs. Comparison was performed between numerical and experimental results to confirm that the numerical approach can properly simulate the loading performance of rock bolts. Based on the modified cableSELs, the influence of the bolt diameter on the performance of rock bolts and the shear stress propagation along the interface between the bolt and the grout were studied. The simulation results indicated that the load transfer capacity of rock bolts rose with the rock bolt diameter apparently. With the bolt diameter increasing, the performance of the rock bolting system was likely to change from the ductile behaviour to the brittle behaviour. Moreover, after the rock bolt was loaded, the position where the maximum shear stress occurred was variable. Specifically, with the continuous loading, it shifted from the rock bolt loaded end to the other end.

Analysis of Composite Bolted Connection Joints Under Out of Plane Loading

The use of composite joints has been increased in recent years in structural applications such as aircraft, civil engineering structure, ship structure, wind energy sector, and automotive industry. In this paper, the behaviour of composite bolted connection joints under out of plane loading is investigated. A parametric study was conducted to study the joint stiffness variation with various geometric parameters, which include the edge distance, bolt diameter, plate width, and the laminate stacking sequence. The experimental work was conducted on GFRP tension clips (L-angle) joint specimens manufactured by the vacuum infusion technique. In the present work, two types of laminates were used, unidirectional laminates [0°]5 with an areal density of 1050 gm/m2, triaxial laminates [−45°/+45°/0°]5 with an areal density of 1200 g/m2. A 3D finite element (FE) model was developed to study the effect of joint parameters on its stiffness. Finite element models were constructed, and the experimental results were used to validate the finite element models. The analysis concluded that the failure load increases when the edge distance to bolt diameter ratio (E/D) increases and the triaxial stacking sequence is better than unidirectional. The (E/D) ratio, the (W/D) ratio and stacking sequence were found to be very significant parameters.