• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.325-328
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• 2006

Joint structures of composite truss bridges can have the same details for the connection between diagonal members and upper concrete slab as the connection between diagonal members and lower concrete slab. Adequate connection details should be decided according to design codes, constructibility, and economical evaluation. It is necessary to clarify the design check items and load transferring mechanism because combined external loads on composite truss bridges are concentrated at the joints. Joints with gusset plates and stud connectors are applied and complicated joint details may arise some problems in construction. This paper deals with experimental evaluation of the joints in composite truss bridges and proper design provisions were investigated to enhance the details. Push-out test specimens with group studs were fabricated and the effects of grouping and bent studs were studied.

• Steel and Composite Structures
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• v.1 no.1
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• pp.17-32
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• 2001

The Rosette-joining system is a completely new press-joining method for cold-formed steel structures. One Rosette-joint has a shear capacity equal to that of approximately four screws or rivets. The Rosette thin-walled steel truss system presents a new fully integrated prefabricated alternative to light-weight roof truss structures. The trusses are built up on special industrial production lines from modified top hat sections used as top and bottom chords and channel sections used as webs which are joined together with the Rosette press-joining technique to form a completed structure easy to transport and install. A single web section is used when sufficient but can be strengthened by double-nesting two separate sections or by using two lateral profiles where greater compressive axial forces are met. An individual joint in the truss can be strengthened by introducing a hollow bolt into the joint hole. The bolt gives the connection capacity a boost of approximately 20%. A series of laboratory tests have been carried out in order to verify the Rosette truss system in practice. In addition to compression tests on individual sections of different lengths, tests have also been done on small structural assemblies and on actual full-scale trusses of a span of 10 metres. Design calculations have been performed on selected roof truss geometries based on the test results, FE-analysis and on the Eurocode 3 and U.S.(AISI) design codes.

• Structural Engineering and Mechanics
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• v.86 no.4
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• pp.461-472
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• 2023

This paper proposes a novel method for increasing the distortional frame rigidity of off-rail box girder bridges for cranes by reinforcing the diaphragm with staggered truss. The study starts by using the Matrix Displacement Method to determine the shear angle of the staggered truss diaphragm under two assumptions: hinge joint and rigid joint. To obtain closed-form solutions for the transversal and longitudinal deformations and warping stress of the crane girder, the study employs the Initial Parameter Method and considers the compatibility of shear deformation at joints between the diaphragms and the girder. The theoretical solutions are validated through finite element analysis, which also confirms that the hinge-joint assumption accurately represents the shear angle of the staggered truss diaphragm in girder distortion. Additionally, the study conducts extensive parameter analyses to examine the impact of staggered truss dimensions on distortional stress and deformation. Furthermore, the study compares the distortional warping stresses of crane girders reinforced with staggered truss diaphragms and those reinforced with perforated ones, emphasizing the importance of incorporating stagger truss in diaphragms. Overall, this paper provides a thorough evaluation of the proposed approach's effectiveness in enhancing the distortional frame rigidity of off-rail box girder bridges for cranes. The findings offer valuable insights into the design and reinforcement of diaphragms using staggered truss to enhance the structural performance of crane girders.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.239-244
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• 2002

The reinforcing bar computation have to be reflected stress distribution and geometrical condition of a comer joint when the closing moment acted at comer joint. This study analyzes stress distribution of a corner joint with statically determinate truss model. Compared with FEM analysis and result of truss model suggested design method consider strengthening efficiency of main reinforcement.

• Steel and Composite Structures
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• v.48 no.6
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• pp.667-679
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• 2023

Concrete filled rectangular steel tubular (CFRST) composite truss girder is composed of the CFRST truss and concrete slab. The failure mechanism of the girder was different under bending and shear failure modes. The bending and shear strength of the girder were investigated experimentally. The influences of composite effect and shear to span ratio on failure modes of the girder was studied. Results indicated that the top chord and the joint of the truss were strengthened by the composited effect. The failure modes of the specimens were changed from the joint on top chord to the bottom chord. However, the composite effect had limited effect on the failure modes of the girder with small shear to span ratio. The concrete slab and top chord can be regarded as the composite top chord. In this case, the axial force distribution of the girder was close to the pin-jointed truss model. An approach of strength prediction was proposed which can take the composite effect and shear to span ratio into account. The approach gave accurate predictions on the strength of CFRST composite truss girder under different bending and shear failure modes.

• Steel and Composite Structures
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• v.31 no.5
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• pp.453-467
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• 2019

Portal frame structures, made up of cold-formed steel trusses, are increasingly being used for lightweight building construction. A novel pin-jointed moment connector, called the Howick Rivet Connector (HRC), was developed and tested previously in T-joints and truss assemblage to determine its reliable strength, stiffness and moment resisting capacity. This paper presents an experimental study on the HRC, in moment resisting cold-formed steel trusses. The connection method is devised where intersecting truss members are confined by a gusset connected by HRCs to create a rigid moment connection. In total, three large scale experiments were conducted to determine the elastic capacity and cyclic behaviour of the gusseted truss moment connection comprising HRC connectors. Theoretical failure loads were also calculated and compared against the experimental failure loads. Results show that the HRCs work effectively at carrying high shear loads between the members of the truss, enabling rigid behaviour to be developed and giving elastic behaviour without tilting up to a defined yield point. An extended gusset connection has been proposed to maximize the moment carrying capacity in a truss knee connection using the HRCs, in which they are aligned around the perimeter of the gusset to maximize the moment capacity and to increase the stability of the truss knee joint.

• The Journal of Korean Academy of Prosthodontics
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• v.22 no.1
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• pp.7-15
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• 1984

A rationale and compendium of treatment for a specific situation of cases have been presented. It consists of a cast metal bar called a truss bar joint removable denture which is soldered to crowns and dowel core on a few remaining teeth, i.e., cuspids or bicuspids. This system gives additional support and retention to the individual teeth and makes possible a more stable removable denture. It is my opinion that the prognosis of the chosen cases may be obtained Successful results when applied on the teeth of less favorable crown-root ratio.

• Structural Engineering and Mechanics
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• v.55 no.4
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• pp.801-813
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• 2015

Flexural stiffness of bridge spans has become even more important parameter since Eurocode 1 introduced for railway bridges the serviceability limit state of resonance. For simply supported bridge spans it relies, in general, on accurate assessment of span moment of inertia that governs span flexural stiffness. The paper presents three methods of estimation of the equivalent moment of inertia for such spans: experimental, analytical and numerical. Test loading of the twin truss bridge spans and test results are presented. Recorded displacements and the method of least squares are used to find an "experimental" moment of inertia. Then it is computed according to the analytical method that accounts for joint action of truss girders and composite deck as well as limited span shear stiffness provided by diagonal bracing. Finally a 3D model of finite element method is created to assess the moment of inertia. Discussion of results is given. The comparative analysis proves efficiency of the analytical method.

• Structural Engineering and Mechanics
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• v.17 no.5
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• pp.627-639
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• 2004

The objective of this research was to evaluate the performance of metal-plate-connected truss joints subjected to cyclic loading conditions that simulated seismic events in the lives of the joints. We also investigated the duration of load factor for these joints. We tested tension splice joints and heel joints from a standard 9.2-m Fink truss constructed from $38-{\times}89-mm$ Douglas-fir lumber: 10 tension splice joints for static condition and for each of 6 cyclic loading conditions (70 joints total) and 10 heel joints for static condition and for each of 3 cyclic loading conditions (40 joints total). We evaluated results by comparing the strengths of the control group (static) with those of the cyclic loading groups. None of the cyclic loading conditions showed any strength degradation; however, there was significant stiffness degradation for both types of joint. The results of this research show that the current duration of load factor of 1.6 for earthquake loading is adequate for these joints.

• Computers and Concrete
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• v.8 no.1
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• pp.59-70
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• 2011

A theoretical model known as the modified rotating-angle softened-truss model (MRA-STM), which is a modification of Rotating-Angle Softened-Truss Model and Modified Compression Field Theory, is presented for the analysis of reinforced concrete membranes in shear. As an application, shear strength and behaviour of reinforced concrete exterior beam-column joints are analysed using the MRA-STM combining with the deep beam analogy. The joints are considered as RC panels and subjected to vertical and horizontal shear stresses from adjacent columns and beams. The strut and truss actions in a beam-column joint are represented by the effective transverse compression stresses and a softened concrete truss in the proposed model. The theoretical predictions of shear strength of reinforced concrete exterior beam-column joints from the proposed model show good agreement with the experimental results.