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It is well known that stainless steel has many advantages such as superb durability, ductility, and corrosion resistance. Thus, the use of stainless steel for various structural members in construction fields is recently increasing. Structural behaviors of bolted and welded connections, compressive and flexural members, beam-column joints, seismic devices etc. have been conducted experimentally and numerically and thus new design methods have been proposed. Hence, in this study, both experiment and finite element analysis were conducted to assess the block shear failure behaviors of double-shear four-bolted connections made of austenitic stainless steel (STS304) with thinner plate and larger end distance, which are beyond the range of previous literature. The main parameter was end distance and edge distance. Block shear strengths by parametric analysis and test results study were compared with design predictions. It is found that current design equations tended to significantly underestimated test and analysis results. Therefore, modified block shear strength equation was recommended for austenitic stainless steel double shear bolted connection treated in this study. [ABSTRACT FROM AUTHOR]

A limited test data are available for double-bolt line connection in a single angle tension member, which failed in block shear. To address this, twelve single angle tension members with a double bolt-line connection was reported in this paper, considering the block aspect ratio and connection length as the test parameters. All the tested specimens were failed in block shear. For the tested specimens, numerical analysis was performed, which shows good agreement with experimental results. Experimental outcomes were then compared with the current design provisions present in the IS 800, AISC, CSA, AIJ, EC 3, SBC, and with other existing proposed models. These standards and models show some discrepancies with regard to the experimental results. This discrepancy was due to the shear failure plane position as assumed in the design standards. Those shear planes were specified in the standards as net and gross shear planes. However, the experimental and numerical investigation shows that between the gross shear plane and the net shear plane lies the actual shear failure plane. Based on this, the block shear mechanism was modified and proposed a rational equation that provides a more exact prediction of block shear capacity than the current design standards and the other existing models. The proposed block shear equation shows the precise forecast for both single and double-bolt line connections used in a single angle tension member. [ABSTRACT FROM AUTHOR]

The experimental and finite element (FE) analyses of the block shear fracture failure in the published literature are limited to the analysis of the fracture on the surface of the gusset plates and connected members without the analysis of the through-thickness fracture in block shear fracture failure. This paper presents the FE analysis of the complete block shear fracture failure covering the analyses of the block shear surface and through-thickness fracture failure. This study reveals the following: The block shear fracture initiation occurs at the tensile plane mid-thickness and not on the tensile plane surface reported in the published literature. The tension plane through-thickness fracture propagation involves mid-thickness-to-surface fracture propagation and not the surface-to-mid-thickness fracture propagation reported in the published literature. The pure shear fracture that is parallel to the tensile loading direction exhibits a surface-to-mid-thickness fracture sequence while the shear lip fracture that is inclined to the tensile loading direction exhibits a mid-thickness-to-surface fracture propagation. This paper thus identifies the accurate fracture initiation location and through-thickness fracture propagation sequence in block shear fracture essential for the accurate and complete analysis of the block shear fracture not hitherto presented in any published literature. [ABSTRACT FROM AUTHOR]

This paper presents the behaviour and design procedure of bolted connections which tend to be sensitive to block shear failure. The finite element method is employed to examine the block shear failure. The research-oriented finite element method (RFEM) model is validated with the results of experimental tests. The validated model is used to verify the component-based FEM (CBFEM) model, which combines the analysis of internal forces by the finite element method and design of plates, bolts and welds by the component method (CM). The CBFEM model is verified by an analytical solution based on existing formulas. The method is developed for the design of generally loaded complicated joints, where the distribution of internal forces is complex. The resistance of the steel plates is controlled by limiting the plastic strain of plates and the strength of connectors, e.g., welds, bolts and anchor bolts. The design of plates at a post-critical stage is available to allow local buckling of slender plates. The prediction of the initial stiffness and the deformation capacity is included natively. Finally, a sensitivity study is prepared. The studied parameters include gusset plate thickness and pitch distance.

Highlights • Definition of block shear failure mechanism of axially-loaded fasteners. • Mechanically-based deterministic block shear failure model for axially-loaded screws. • Comprehensive analysis of all model parameters, their background and adequate settings. • Presentation of two newly developed test setups. • Experimental investigations of axially-loaded screws at a thread-fibre angle of 90°. • Successful model validation with respect to failure sequence, capacity and stiffness. Abstract Self-tapping screws are fasteners that are versatilely applicable in timber engineering. For the design of such screw connections, preferential axial-loading, all possible failure mechanisms have to be considered. Recently, in compact groups of axially-loaded screws the block shear failure mechanism, which has not been investigated so far, turned out to fail rather brittle at load levels lower than currently allowed. This failure mechanism is defined as failure of (rolling) shear and/or tension perpendicular to grain planes encompassing the group of screws. This failure mechanism was observed in groups given a number of different parameter settings, i.e. thread-fibre angles of 90° and 45°, glulam, structural timber and cross laminated timber and various group designs. This paper focuses on groups of axially-loaded screws in glulam and solid timber of Norway spruce (Picea abies) and inserted at a thread-fibre angle of 90°. Varying group sizes, loading and supporting distances and group designs, i.e. various penetration lengths l ef and spacing in and perpendicular to grain, a 1 and a 2 , respectively, are analysed by two different "push-pull"-test setups. To predict the block shear capacity and failure characteristics of such groups of screws and to separate this failure mechanism from other failure mechanisms, a mechanical-based block shear model was established. This parallel acting spring model considers load sharing and redistribution between concerned failure planes and depends on a number of material, geometrical and stress distribution parameters. To ensure a reasonable parameter setting, background and potential influencing parameters on each model parameter are discussed. In validation, the model shows overall good predictions of capacities, failure mechanisms and failure sequence for all test series involved. It turned out that the current regulations, comprising the definition of minimum spacing together with minimum edge and end distances, are not sufficient for controlling this three-dimensional block shear failure. In addition, the consideration of the number of screws in the group as well as the penetration length is required. [ABSTRACT FROM AUTHOR]

Highlights: [•] For the first time, demonstrates that a block shear failure by the shear rupture and tensile yielding mechanism is possible. [•] Describes two phenomena that could be misidentified as the simultaneous shear and tensile ruptures mechanism. [•] Proposes two equations for determining a staggered block shear capacity and a split block shear capacity, respectively. [Copyright &y& Elsevier]

Abstract: The 2007 collapse of the I-35W Bridge in Minneapolis, Minnesota led to additional load rating requirements for gusset plates. The Federal Highway Administration provided the direct tension and block shear methods to assess tensile capacity for use in load rating, as well as a mechanics based method to assess shear capacity on critical planes. However, the three methods provide limited information about ultimate behavior for complex connections. Using finite elements, the authors modeled the connection from Whitmore’s 1952 study to evaluate the plate capacity and failure mechanism. The analysis showed that the direct tension method was conservative, but predicted neither capacity nor behavior. Model performance corresponded well with the critical block shear capacity load in the left diagonal, and shear capacity on the gross horizontal plane. Yielding on this plane began around critical bolt holes and spread to either side of the plate, forming the critical failure mechanism. [Copyright &y& Elsevier]

Block shear is a limit state that should be accounted for during the design of steel tension members. Current design equations are not based on analytical findings and fail to predict failure modes of tested specimens. A study has been conducted to develop simple block shear load capacity prediction equations that are based on finite element analysis. Over a thousand nonlinear analyses were performed to identify the important parameters that influence block shear capacity. In addition, the effects of eccentric loading were investigated. Based on the parametric study block shear load capacity prediction equations were developed. The predictions of the developed equations were compared with the experimental findings and were found to provide estimates with acceptable accuracy. [Copyright &y& Elsevier]

This paper presents the behaviour and design procedure of bolted connections which tend to be sensitive to block shear failure. The finite element method is employed to examine the block shear failure. The research-oriented finite element method (RFEM) model is validated with the results of experimental tests. The validated model is used to verify the component-based FEM (CBFEM) model, which combines the analysis of internal forces by the finite element method and design of plates, bolts and welds by the component method (CM). The CBFEM model is verified by an analytical solution based on existing formulas. The method is developed for the design of generally loaded complicated joints, where the distribution of internal forces is complex. The resistance of the steel plates is controlled by limiting the plastic strain of plates and the strength of connectors, e.g., welds, bolts and anchor bolts. The design of plates at a post-critical stage is available to allow local buckling of slender plates. The prediction of the initial stiffness and the deformation capacity is included natively. Finally, a sensitivity study is prepared. The studied parameters include gusset plate thickness and pitch distance. [ABSTRACT FROM AUTHOR]