Stud Bolts Research Articles

The treatment of displaced intra-articular calcaneal fractures by "/\" shape incision with compression fixation and stud bolts

Objective To explore the method and efficacy of the treatment for displaced intra-articular calcaneal fractures by lateral / shape with compression fixation and stud bolts.Methods From August 2010 to November 2011,used the lateral / shape incision,namely the straight front of achilles tendon and the sinus tarsi oblique incision,140feet with displaced intra-articular calcaneal fractures in 130 patients were treated with calcaneal anatomical plate and compression fixation with stud bolts.There were 117 males and 13 females,with an average age of 42.3 years.According to Sanders classification,the fracture patterns include 49 cases for type Ⅱ,75 for type Ⅲ,and 16 for type Ⅳ.The B（o）hler and Gissane angle as well as the varus angle,the displacement of subtalar articular surface,the width,height and length of the calcaneum were measured on pre-and post-operative radiographs.The Maryland and AOFAS foot score were used to assess the results.Results One hundred and thirty patients got followed up with an average of 20 months (range,15-31 months).There were no edge necrosis and wound infection.The time of fracture union was 54.51 ±20.38 d (range,45-86 d).The amount of bleeding was 194.24±104.17 ml.Accorrding to the preoperative and postoperative radiographs,the mean B(o)hler angle was 6.27°±11.81° and 27.21°±8.28°; the mean Gissane angle was 108.36°±21.77° and 117.47°±12.93°,the mean calcaneal width was 47.35±5.85 mm and 35.96±4.14 mm,the mean calcaneal height was 39.79±5.85 mm and 47.64±3.83 mm,the mean calcaneal length was 78.30±5.81 mm and 79.41±5.30 mm.Based on the Maryland foot score,the excellent and good rate was 92.86％ (130/140).Based on the AOFAS foot score,the excellent and good rate was 95.71％ (134/140).Compared with the normal side,the ankle varus of 12feet were restriction for 5°-8°,3 feet were sufferd for subtalar arthritis.Conclusion Lateral / shape incision with compression fixation and stud bolts to is a safe and effective method for the treatmeat for the displaced intra-articular calcaneal fractures,significantly reducing and avoiding the wound complications,restoring calcaneal anatomical morphology and the surface of subtalar joint.The compression fixation with stud bolts is reliable and stability,it can promote the early healing of fractures. Key words: Calcaneus; Fractures bone; Fracture fixation, internal

Stud Bolt Effects on the Bearing Performance of Pseudo Strain-Hardening Cementitious Composite (PSH2C) Wall-Steel Coupling Beam Connections

Recently, hybrid coupled shear system, where steel coupling beam couple two or more RC shear walls are frequently applied for medium and high-rise building subjected to earthquake. This paper addresses the seismic performance of PSH2C wall - steel coupling beam with stud bolts in the connection region. Test variables included stud bolts in embedded steel coupling beam and types of material, such as PSH2C and concrete, in the wall. The results show that PSH2C wall – beam connections (PSH2C-ST and PSH2C-SB) exhibit better hysteretic response than normal concrete wall – beam connections (HCWS-ST and HCWS-SB).

Analysis of the integrity of a single stud assembly with externally corroded nuts

The aim of this study was to determine whether a single 7/8′′ nominal diameter stud bolt and nuts assembly would fail to perform its required function in a flange assembly when the nut was corroded. This work was undertaken to form a basis for further work in development of a fitness-for-service assessment for corroded nuts. No current quantitative assessments exist for this area. A failure criterion was defined as a minimum 206.8 MPa stress in the stud, based on the bolting requirements stated in ASME B16.5-2003 pipe flanges and flanges fittings. A simple test rig was manufactured for testing the compliance of the corroded nuts subjected to the 206.8 MPa stress level and the corrosion was simulated by removing uniform layers of material from the surface of the nut. Finite element analysis (ANSYS 12.0) was also performed to evaluate the test rig and to consider the interaction between the nut and stud at the thread roots. It was found that no failure occurred in the threading and that failure of the assembly only occurred when there was a >60% material loss from the nut. The failure mode experienced was deformation of the flange plate. This analysis proved that a nut can experience significant effective material loss without damaging the flange integrity.

드라이빙핀전용 전단연결재를 이용한 합성보의 탄소성 거동

합성보는 철골보와 콘크리트슬래브를 스터드볼트로 일체화한 구조이며, 일반적으로 용접을 이용한 스터드볼트(Stud Bolts)가 연결재로 많이 사용된다. 그러나, 스터드볼트는 감전사고와 같은 전기재해나 용접불량 등 문제점을 가지고 있다. 따라서, 드라이빙핀을 이용한 기계적 접합이 대안으로 대두되고 있다. 본 연구는 드라이빙핀 전용 제안형 전단연결재를 이용한 합성보의 횡하중(지진하중이나 풍하중)시 구조적 성능을 평가하고자 한다. 기존형 합성보과 제안형 합성보는 안정된 탄소성 거동을 나타내었으며 기둥주변에서 콘크리트 압괴로 내력이 저하되었다. 따라서, 제안형 합성보는 기존형 합성보를 대체할 수 있을 것으로 판단된다. The adoption of a composite beam system is regarded as a simple but effective solution because it improves the overall stiffness, strength and stability of the structure by welding shear studs. However, welding shear studs poses problems including electric shock and weld defects. Mechanical methods have emerged as an alternative to metallurgical methods for connecting the H-beam and shear connector. Four specimens were tested in order to compare the structural behavior of the proposed composite beams with that of the classical composite beam given the condition of horizontal loading. With the original composite beam (FCB-SB specimen) using stud bolts, hysteresis loops are stable, but its strength decreased with the crashing of the concrete slab around the column. The suggested composite beams using shear connectors also yielded stable hysteresis loops. Consequently, use of the suggested composite beams instead of the original composite beam are recommended.

Lubrication properties of silver-palladium alloy prepared by ion plating method for high temperature stud bolt

As a solid lubricant, silver-palladium (Ag-Pd) alloy coating was investigated for the application to high temperature stud bolt. A glue layer nickel (Ni) film was deposited on the surface of the hex bolt sample and then Ag-Pd alloy coating was performed on it using ion plating method. The friction coefficient of Ag-Pd alloy film coated bolt was lower than that of N-5000 oil coated bolt by the result of axial force measurement. The cyclic test of heat treatment was conducted to evaluate the durability of Ag-Pd alloy film coated bolt. In a cycle, sample was assembled into the block using torque wrench, followed by heating and disassembling. It was not successful to disassemble the N-5000 oil coated bolt from the block after only one cycle. However, the Ag-Pd alloy film coated bolt was able to be disassembled softly till 12 cycles.

Microstructure and Mechanical Property of 5000 Series Aluminum Stud Joint with Zinc Insert Using Friction Welding

Friction stud welding with zinc insert was applied to 5000 series aluminum alloys. A cone-shaped A5056 stud bolt was successfully friction-welded onto A5083 plate at low torque using zinc insert compared to that without zinc insert. This is considered to be contributed by a eutectic reaction between aluminum and zinc, which can effectively remove the oxide film and promote the joining. With bigger torque and longer welding time, the amount of residual zinc was reduced and high strength was achieved. On the other hand, a twist break between the stirred zone and the stud bolt increased during friction and this causes the decrease of tensile strength of the joint after a certain amount of torque. The results of micro-tensile test showed that strength at the edge of joint interface was higher than that at the center area regardless of zinc insert. From the experimental results, the joining process of the present friction stud welding classified into five processes, i.e. wear of stud bolt, start of joining, increase of tensile strength, decrease of tensile strength, and fracture during friction.

617 三次元有限要素解析による植え込みボルトの力学特性の評価(GS-3 材料検査および評価)

617 三次元有限要素解析による植え込みボルトの力学特性の評価(GS-3 材料検査および評価)

A study on the seismic performance of concrete-filled square steel tube column-to-beam connections reinforced with asymmetric lower diaphragms

This paper studies the development of the through-type concrete-filled square steel tube column-to-beam connection, reinforced with an asymmetric lower diaphragm. This type of connection can be used in weak-earthquake regions such as Korea. A simple tension test was performed on the suggested lower diaphragms and the combined cross diaphragm in order to confirm their tensile behavior. Subsequently, four types of concrete-filled square steel tube column-to-beam connection (with combined cross diaphragm, nothing, horizontal T-bar and vertical plate as lower diaphragm) were fabricated in actual size and tested according to the ANSI/AISC SSPEC 2002 cyclic loading program. The horizontal T-bar and stud bolts in the vertical plates were designed to transmit the tensile stress from the bottom flange of the beam to the filled concrete. All the test specimens satisfied the 0.01 radian inelastic rotation capacity requirements for the composite ordinary moment frame (C-OMF) of the AISC seismic provisions. It was concluded that the suggested simplified lower diaphragms have sufficient strength, stiffness and plastic deformation capacity to be used in the field.

Silver-palladium alloy deposited by DC magnetron sputtering method as lubricant for high temperature application

The silver-palladium(Ag-Pd) alloy coating as a solid lubricant was investigated for its application to the high temperature stud bolts used in nuclear power plants. A hex bolt sample was prepared in the following steps: 1) bolt surface treatment using alumina grit blasting for cleaning and increasing the surface area; 2) nickel(Ni) film coating as a glue layer on the surface of the bolt; and 3) Ag-Pd alloy coating on the Ni film. The films were deposited by using a direct current(DC) magnetron sputtering system. The thickness and composition of the Ag-Pd alloy film have effect on the friction coefficient, which was determined using axial force measurement. A 500 nm-thick Ag-Pd (80:20, molar ratio) alloy film has the lowest friction coefficient of 0.109. A cyclic test was conducted to evaluate the durability of bolts coated with either the Ag-Pd (80:20) alloy film or N-5000 oil. In a cycle, the bolts were inserted into a block using a torque wrench, which was followed by heating and disassembling. After only one cycle, it was not possible to remove the bolts coated with the N-5000 oil from the block. However, the bolts coated with the Ag-Pd (80:20) alloy could be easily removed up until 15 cycles.

Optimum Dimensions of Thin Walled Tube on the Mechanical Performance of Super Stud Bolt

The bolts and nuts are widely used in various fields as important joining elements with long history. However, loosening induced by the vibration and external loads is still a big problem. And the loosening sometimes causes very serious accident without notice. This paper deals with a special stud bolt named “Super Stud Bolt (SSB)” which can prevent loosening effectively. There is a thin walled tube between the upper and lower threads, which can be deformed along the axial direction so that the phase difference is produced and SSB is developed. This phase difference induces the contrary force on the surfaces of the upper and lower threads, which brings out the anti-loosening performance. In this study, the processing and fastening-loosening courses are simulated with the finite element method. And the anti-loosening performance is analyzed and realized. In addition, the anti-loosening performances under various phase differences are compared and finally best dimensions for SSB are examined.

Study of partially encased composite beams with innovative position of stud bolts

In this article, static behavior of three partially encased composite beams under flexural condition is investigated in the context of studying some alternative positions for the headed studs. Shear resistance between the I -shaped beam and the concrete was provided by headed studs in two positions: vertically welded on the bottom flange and horizontally welded on the faces of the web. Experimental results show that the headed studs provide the composite action and increase the bending strength. The most remarkable position seems to be the headed studs vertically welded on the bottom flange. An analytical method to estimate the bending capacity of the encased beams is also proposed, giving a good prediction of the experimental results

Optimum Dimensions of Thin Walled Tube on the Mechanical Performance of Super Stud Bolt

The bolts and nuts are widely used in various fields as important joining elements with long history. However, screw loosening is easily induced by vibration and external loads, and sometimes causes very serious accident without notice. In this paper, a special stud bolt named “Super Stud Bolt (SSB)” is studied, which can prevent loosening effectively. Between the upper threads and the lower threads, there is a thin walled tube which can be deformed along the axial direction so that the phase difference is designed and SSB is developed. During fastening, this phase difference induces the contrary forces on the surfaces of the upper threads and the lower threads, which bring out the antiloosening performance. In this study, both courses of processing and fastening are simulated, and the relationship between axial force and displacement is illustrated with the finite element method. In this analysis, the large plastic strains and elastic-plastic large deformation theory are applied to 4 nodes axial symmetric FEM models. Through the comparison among the results, the desirable range of the phase difference of lower and upper threads is decided. Since the thin walled tube is the heart of anti-loosening mechanism, optimum original dimensions are discussed in this study.

Shear transfer mechanisms in composite columns: an experimental study

In the design of concrete filled composite columns, it is assumed that the load transfer between the steel tube and concrete core has to be achieved by the natural bond. However, it is important to investigate the mechanisms of shear transfer due to the possibility of steel-concrete interface separation. This paper deals with the contribution of headed stud bolt shear connectors and angles to improve the shear resistance of the steel-concrete interface using push-out tests. In order to determine the influence of the shear connectors, altogether three specimens of concrete filled composite column were tested: one without mechanical shear connectors, one with four stud bolt shear connectors and one with four angles. The experimental results showed the mechanisms of shear transfer and also the contribution of the angles and stud bolts to the shear resistance and the force transfer capacity.

Application of Ultrasonic Phased Array Techniques for Inspection of Stud Bolts in Nuclear Power Plants

The reactor vessel body and closure head are fastened with the stud bolt that is one of crucial parts for safety of the reactor vessels in nuclear power plants. It is reported that the stud bolt is often experienced by fatigue cracks initiated at threads. Stud bolts are inspected by the ultrasonic technique during the overhaul periodically for the prevention of failure which leads to radioactive leakage from the nuclear reactor. The conventional ultrasonic inspection for stud bolts was mainly conducted by reflected echo method based on shadow effect. However, in this technique, there were numerous spurious signals reflected from every oblique surfaces of the thread. In this study, ultrasonic phased array technique was applied to investigate detectability of flaws in stud bolts and characteristics of ultrasonic images corresponding to different scanning methods, that is, sector and linear scan. For this purpose, simplified stud bolt specimens with artificial defects of various depths were prepared.

Bearing Strength of Hybrid Coupled Shear Wall Connections

Due to lack of information, current design methods to calculate bearing strength of connections are tacit about cases in which hybrid coupled walls have connection details of stud bolts and horizontal ties. In this study, analytical study was carried out to develop model for calculating the connections strength of embedded steel section. The bearing stress at failure in the concrete below the embedded steel coupling beam section is related to the concrete compressive strength and the ratio of the width of the embedded steel coupling beam section to the thickness of the shear walls. Experiments were carried out to determine the factors influencing the bearing strength of the connection between steel coupling beam and reinforced concrete shear wall. The test variables included the reinforcement details that confer a ductile behavior in connection between steel coupling beam and shear wall, i. e., the auxiliary stud bolts attached to the steel beam flanges and the transverse ties at the top and the bottom steel beam flanges. In addition, additional test were conducted to verify the strength equations of the connection between steel coupling beam and reinforced concrete shear wall. The results of the proposed equations in this study are in good agreement with both our test results and other test data from the literature.

Failure of a stud bolt in a ring spinning frame textile machine

A failure investigation has been conducted on a stud bolt used in a ring spinning frame textile machine, which is made of austenitic stainless steel (AISI 304). The stud bolt has been found fractured after about 300 h in service. An evaluation of the failed stud bolt was undertaken to assess its integrity that included a visual examination, photo documentation, chemical analysis, micro-hardness measurement, tensile testing, and metallographic examination. The failure zones were examined with the help of a scanning electron microscope (SEM) equipped with EDX facility. Results indicate that the stud bolt fractured in rotating bending fatigue.

The bearing strength of steel coupling beam-reinforced concrete shear wall connections

Increasingly, engineers are designing hybrid and mixed building systems of structural steel and reinforced concrete to produce more efficient structures than can be realized using either material alone. In particular, hybrid coupled shear wall of them are known to be efficient lateral load resisting system. However, due to lack of information, current design equations to compute the bearing strength of steel coupling beam–wall connections in a hybrid coupled shear walls are tacit about cases in which the beams have connection details to the walls that include stud bolts and horizontal ties in hybrid coupled shear walls. There were carried out experimental and analytical studies on steel coupling beam–wall connections in a hybrid wall system. Experimental study was carried out to verify the bearing strength of steel coupling beam–wall connections. The test variables included the reinforcement details that confer a ductile behavior on the steel coupling beam–wall connection, i.e., the stud bolts and the horizontal ties in the steel coupling beam–wall connections. The equations proposed in this study to predict strength for steel coupling beam-reinforced concrete shear wall connections were in good agreement with both our test results and other test data from the literature.

Retrofitting of Tautendorf Valley Bridge in Highway A9 Berlin, Germany

This article describes the design, analysis and construction of a widened road bridge in Germany. The previous bridge, using a solidweb girder method of construction, was considered historically important and so incorporated to the new structure. A new single-cell, externally prestressed box section was designed to form a new superstructure alongside the existing bridge, built on tapering pier slabs. Its cantilever arm was positioned over the load-bearing structure of the existing bridge to reduce non-functional excess width. Structural design of load-bearing characteristics used a bond between the deck slab and inner main girders. A stability analysis was carried out to provide a sufficient load-bearing capacity: stud bolts were fitted near the reinforced concrete joists on the inner main girder and near the cross girders, to secure location and transfer shear forces. Fracture mechanics analysis was used to predict the damage tolerance of the structure and reinforcement was carried out on the inner main girder.

Seismic behaviour of coupling beams in a hybrid coupled shear walls

Steel coupling beams in a hybrid coupled shear wall provide a viable alternative for concrete coupling beams coupling individual reinforced concrete wall piers. Due to the lack of information, current design methods for calculating embedment lengths are silent about cases in which hybrid coupled walls have connection details of stud bolts and horizontal ties. In this work, an analytical study was carried out to develop a model for calculating the embedment lengths of embedded steel sections. Five models for calculating embedment lengths in a hybrid coupled wall are developed as variations of the Prestressed Concrete Institute guidelines for steel brackets attached to reinforced concrete columns. In addition, experimental studies on the hybrid coupled shear wall were carried out. The main test variables were the ratios of the coupling beam strength to the connection strength. The test results indicate that it is more advantageous to design the coupling beams as shear yielding members since the shear-critical coupling beam exhibits a more desirable mode of energy dissipation than the flexure-critical coupling beam.

Reviews Of Acoustical Patents

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