Strength and Stiffness of Segmented Compression Part Beam Made of Sliced Laminated Bamboo Due to Transverse Load on Shear Failure Mode

Bond properties of ceramic concrete reinforced by bamboo bar were investigated based on pull-out tests. The influences of strength grade of ceramic concrete, material type, bond length, side length and notch spacing of bamboo bar on the bond strength between the bamboo bars and ceramic concrete were studied. The results show that the bond failure mode of ceramic concrete reinforced by bamboo bar without notch is majorly pulling-out failure, however, ceramic concrete reinforced by restructured bamboo (RB) bar with notch appears shear failure mode. The ultimate bond strength of ceramic concrete reinforced by RB bars is higher than that of ceramic concrete reinforced by laminated bamboo (LB) bar, which is close to that of ceramic concrete reinforced by plastic bars,but lower than that of ceramic concrete reinforced by steel bars under the same condition. When the notch spacing is 15 mm, the bond strength of ceramic concrete reinforced by RB bars is the highest. The conclusions can be usable for the the constitutive relationship of ceramic bamboo-reinforced concrete.

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Pullout Behavior of Steel Beam-Concrete Wall Pinned Joints with T- shaped Connectors

IABSE Congress, New York, New York 2019: The Evolving Metropolis ◽

10.2749/newyork.2019.1747 ◽

2019 ◽

Author(s):

He Zhao ◽

Xin Nie ◽

Dan Zhu ◽

Mu-Xuan Tao

Keyword(s):

Failure Mode ◽

Failure Modes ◽

Shear Failure ◽

Parameter Analysis ◽

Steel Beam ◽

Concrete Wall ◽

Concrete Core ◽

Key Factor ◽

Strength And Stiffness ◽

Pinned Joints

Nowadays, reinforced concrete core wall-steel frame hybrid structural systems are widely used in mid-rise and high-rise buildings. In this type of structural system, the pulling resistant behavior of the steel beam-concrete wall joints (SBCW joints for short) plays a very important role in the seismic behavior. In this study, the pullout behavior of a new type of SBCW pinned joints with T-shaped steel connectors is tested, and the load- displacement curves and failure modes of the specimens are analyzed. Two failure modes are observed in the experiments: one is punching shear failure mode characterized by the pullout of concrete pyramid with lower strength and stiffness, and the other is web yield failure mode characterized by the yield of the web plate of the connector with higher strength and stiffness. The key factor to determine the failure mode is the embedded depth of the connector. Additionally, finite element models for the SBCW joint are established and nonlinear elastic-plastic analysis is carried out, which can predict the failure modes and pulling resistant capacity of the specimens with good accuracy. Based on the numerical model, a parameter analysis is conducted to study the influence of more factors on the capacity of the SBCW joint.

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Machine learning-based failure mode identification of RCSPSW

IABSE Congress, Christchurch 2021: Resilient technologies for sustainable infrastructure ◽

10.2749/christchurch.2021.1150 ◽

2021 ◽

Author(s):

Dongqi Jiang ◽

Shanquan Liu ◽

Tao Chen ◽

Gang Bi

Keyword(s):

Machine Learning ◽

Failure Mode ◽

Failure Modes ◽

Shear Failure ◽

Tall Buildings ◽

Shear Walls ◽

Superior Performance ◽

Ann Model ◽

Mode Recognition ◽

Wide Range

Reinforced concrete – steel plate composite shear walls (RCSPSW) have attracted great interests in the construction of tall buildings. From the perspective of life-cycle maintenance, the failure mode recognition is critical in determining the post-earthquake recovery strategies. This paper presents a comprehensive study on a wide range of existing experimental tests and develops a unique library of 17 parameters that affects RCSPSW’s failure modes. A total of 127 specimens are compiled and three types of failure modes are considered: flexure, shear and flexure-shear failure modes. Various machine learning (ML) techniques such as decision trees, random forests (RF), K-nearest neighbours and artificial neural network (ANN) are adopted to identify the failure mode of RCSPSW. RF and ANN algorithm show superior performance as compared to other ML approaches. In Particular, ANN model with one hidden layer and 10 neurons is sufficient for failure mode recognition of RCSPSW.

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An Experimental Study on Mechanical Behavior of Parallel Joint Specimens under Compression Shear

Advances in Civil Engineering ◽

10.1155/2018/5428670 ◽

2018 ◽

Vol 2018 ◽

pp. 1-12

Author(s):

Fei Wang ◽

Ping Cao ◽

Yu Chen ◽

Qing-peng Gao ◽

Zhu Wang

Keyword(s):

Shear Stress ◽

Shear Strength ◽

Failure Mode ◽

Shear Failure ◽

Strain Curve ◽

Shear Loading ◽

Plane Shear ◽

Joint Spacing ◽

Dip Angle ◽

Joint Inclination

In order to investigate the influence of the joint on the failure mode, peak shear strength, and shear stress-strain curve of rock mass, the compression shear test loading on the parallel jointed specimens was carried out, and the acoustic emission system was used to monitor the loading process. The joint spacing and joint overlap were varied to alter the relative positions of parallel joints in geometry. Under compression-shear loading, the failure mode of the joint specimen can be classified into four types: coplanar shear failure, shear failure along the joint plane, shear failure along the shear stress plane, and similar integrity shear failure. The joint dip angle has a decisive effect on the failure mode of the specimen. The joint overlap affects the crack development of the specimen but does not change the failure mode of the specimen. The joint spacing can change the failure mode of the specimen. The shear strength of the specimen firstly increases and then decreases with the increase of the dip angle and reaches the maximum at 45°. The shear strength decreases with the increase of the joint overlap and increases with the increase of the joint spacing. The shear stress-displacement curves of different joint inclination samples have differences which mainly reflect in the postrupture stage. From monitoring results of the AE system, the variation regular of the AE count corresponds to the failure mode, and the peak value of the AE count decreases with the increase of joint overlap and increases with the increase of joint spacing.

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Experimental Study on the Shear Performance of Shallow Hinge Joints for Prefabricated Hollow Slab Bridges

Advances in Civil Engineering ◽

10.1155/2018/3962942 ◽

2018 ◽

Vol 2018 ◽

pp. 1-8

Author(s):

Hanbin Yi ◽

Chuanxi Li ◽

Li Dai

Keyword(s):

Shear Stress ◽

Failure Mode ◽

Shear Failure ◽

Internal Force ◽

Force Transmission ◽

Transmission Performance ◽

Joint Stress ◽

Hinge Joint ◽

Vehicle Load ◽

Joint Fracture

To investigate whether shallow hinge joint fracture was caused by shear stress or flexural stress, during the demolition and reconstruction of Xiaojiang River bridge, two original girders were collected and shipped to the lab, and the shallow hinge joint between the two girders was rebuilt. Tests were performed to investigate the cracking load, failure mode, and force transmission performance of the hollow slab girder and shallow hinge joint under vehicle load. The test result shows that under eccentric load, when the load increases to 365 kN, the midspan bottom slab of the testing girder starts to fracture; as the load increases to 560 kN, the roof slab of the testing girder starts to fracture; the hinge joint has a maximum horizontal opening of 0.153 mm and vertical relative displacement of 0.201 mm; during the entire test loading process, the shallow hinge joint structure does not develop fracture and shear failure; and the shallow hinge structure demonstrates excellent shear stress transmission performance. In addition, based on hinge slab theory, the hinge joint internal force under vehicle load was calculated. Based on ACI 318-05 specification, CAN/CSA-S6-00, and JTG D61-2005, the hinge joint shear bearing capacity was calculated. Hinge joint stress resistances calculated from the three specifications all exceed the internal force. Among them, the calculation results from ACI 318-05 and CAN/CSA-S6-00 are similar, while the result from JTG D61-2005 specification significantly exceeds the internal force, which is mainly because the designed concrete direct shear strength fvd in the Chinese specification does not consider factors such as bonding surface coarseness, concrete pouring sequence, and material properties. Theoretical calculations and tests show that the actual failure mode of the shallow hinge joint in prefabricated hollow slab girder bridges is not caused by shear stress.

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Mechanical Model of Roughened Concrete of Existing Members for Shear Failure Mode

10.21012/fc10.235482 ◽

2019 ◽

Author(s):

Y Katagiri

Keyword(s):

Failure Mode ◽

Mechanical Model ◽

Shear Failure

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Mechanical Respond and Failure Mode of Large Size Honeycomb Sandwiched Composites under In-Plane Shear Load

Molecules ◽

10.3390/molecules24234248 ◽

2019 ◽

Vol 24 (23) ◽

pp. 4248 ◽

Cited By ~ 1

Author(s):

Wang ◽

Liu ◽

Zhang ◽

Wan ◽

...

Keyword(s):

Theoretical Analysis ◽

Shear Strain ◽

Failure Mode ◽

Field Distribution ◽

Shear Failure ◽

Buckling Load ◽

Analysis Method ◽

Plane Shear ◽

Large Size ◽

Honeycomb Sandwich

The present work focuses on the in-plane shear respond and failure mode of large size honeycomb sandwich composites which consist of plain weave carbon fabric laminate skins and aramid paper core. A special size specimen based on a typical element of aircraft fuselage was designed and manufactured. A modified in-plane shear test method and the corresponding fixture was developed. Three large size specimens were tested. The distributed strain gauges were used to monitor the mechanical response and ultimate bearing capacity. The results show that a linear respond of displacement and strain appears with the increase of the load. The average shear failure load reaches 205.68 kN with the shear failure occurring on the face sheet, and the maximum shear strain monitored on the composite plate is up to 16,115 με. A combination of theoretical analysis and finite element method (FEM) was conducted to predict the shear field distribution and the overall buckling load. The out-of-plane displacement field distribution and in-plane shear strain field distribution under the pure shear loading were revealed. The theoretical analysis method was deduced to obtain the variation rule of the shear buckling load. A good agreement was achieved among the experiment, theoretical analysis, and FEM results. It can be concluded that the theoretical analysis method is relatively conservative, and the FEM is more accurate in case of deformation and strain. The results predicted by h element and p element methods are very close. The results of the study could provide data support for the comprehensive promotion of the design and application of honeycomb sandwich composites.

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Experimental Study on Bending Performance of Composite Sandwich Panel with New Mixed Core

MATEC Web of Conferences ◽

10.1051/matecconf/201927502018 ◽

2019 ◽

Vol 275 ◽

pp. 02018

Author(s):

Jing Zhang ◽

Xiamin Hu ◽

Wan Hong ◽

Bing Zhang ◽

Chengli Zhang

Keyword(s):

Experimental Investigation ◽

Polyurethane Foam ◽

Failure Mode ◽

Shear Failure ◽

Sandwich Panels ◽

Tensile Failure ◽

Bending Test ◽

Bending Performance ◽

Composite Sandwich Panels ◽

Composite Sandwich

This paper presents an experimental investigation of bending performance of composite sandwich panels with new mixed core, sandwich panels were tested by four-point bending test. Parametric study was conducted to investigate the influence of different core materials on the failure mode, ultimate bearing capacity, stiffness and ductility of composite sandwich panels. The results of the experimental investigation showed that the mixed core can change the failure mode of sandwich panels. The failure mode of wooden panels is characterized by tensile failure of bottom wood, and the failure mode of composite sandwich panels with wood core is that the surface layer and core are stripped and the webs are damaged by shear, while the failure mode of composite sandwich panels with wood and polyurethane foam mixed core is the shear failure of the web. Composite sandwich panels with GFRP-wood-polyurethane foam core have better bending performance and can effectively reduce the weight of panels.

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