scholarly journals Influence of the Force Arm on the Flexural Performance of Prestressed Glulam Beams

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Lidan Mei ◽  
Nan Guo ◽  
Hongliang Zuo ◽  
Ling Li ◽  
Guodong Li
Keyword(s):  
Bearing Capacity ◽  
Failure Mode ◽  
Design Method ◽  
Wood Structures ◽  
Glulam Beam ◽  
Flexural Performance ◽  
Wood Construction ◽  
Resistance Moment ◽  
String Structure ◽  
Mode Stress

In recent years, extensive attention has been drawn to prefabricated buildings, particularly wood construction. Glulam beams are the major supporting components of modern wood buildings. Since the force arm is the most critical indicator to evaluate the resistance moment of the glulam beam string structure, it is necessary to further study the influence of the force arm on the mechanical properties of the glulam beam string structure. We tested the flexural performance of 15 prestressed glulam beams, which were divided into two groups (A and B) to, respectively, research the influences of the string arm and the end arm on the bearing capacity, failure mode, stress distribution, and deformation performance of glulam beams. The results showed that when the height of the end arm remained constant and the string arm increased from 90 mm to 130 mm and 170 mm, the bearing capacity of the beam increased by 6.77% and 17.22%, respectively. Moreover, as the depth of the compression zone of the glued timber beam gradually increased, the failure mode of the beam changed from the brittle tension failure of the beam bottom to the ductile compression failure of the beam top. When the height of the string arm remained constant and the end arm increased from 10 mm to 30 mm and 50 mm, the bearing capacity of the beam increased by 4.27% and 8.13%, respectively. The beam had no significant change in the failure mode, while it could bear the stress more uniformly. Based on the experimental results and principles of equilibrium, moment equilibrium, and similar triangle, we calculated the ultimate bearing capacity of the glulam beam and proposed a design method for durable wood structures.

scholarly journals Experimental Research on Bending Bearing Capability of Grouted Double Mortise-Tenon Joint for Prefabricated Metro Station Structure

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Xiuren Yang ◽  
Fang Lin ◽  
Meiqun Huang
Keyword(s):  
Bearing Capacity ◽  
Failure Mode ◽  
Characteristic Curve ◽  
Test Results ◽  
Underground Structures ◽  
Metro Station ◽  
Prototype Test ◽  
Resistance Moment ◽  
Ultimate Failure ◽  
Bearing Characteristic

The grouted mortise-tenon joint, invented as the connection between the large prefabricated elements, is the most important component in the prefabricated underground structures. This paper conducts analysis of load-carrying capacity performance and failure mode with 1 : 1 prototype test in key working direction of different double mortise-tenon joint types for the prefabricated metro station. The resistance moment is developed and used to analyze the bending bearing characteristic curve, and the corresponding test results of each stage of the characteristic curve are described in detail. In addition, the bending bearing performance of different types of double-tenon joints under different load conditions is compared. The test results clarify the ultimate failure mode of double-tenon joint and the variable bearing capacity characteristics of the joint with the increase in axial load and explain the bearing performance of each stage. It is also found the auxiliary pretightening device is helpful to delay the appearance of cracks and improve the bearing capacity, especially when it is set on the tension side. The research results have important application value for the joint design of prefabricated metro station structures.

scholarly journals Experimental Study on Flexural Performance of Regulated Reinforced Glulam Beam after Long-Term Loading

2021 ◽  
Vol 13 (10) ◽  
pp. 5556
Author(s):  
Nan Guo ◽  
Chao Yang ◽  
Ling Li ◽  
Guodong Li ◽  
Yan Zhao
Keyword(s):  
Bearing Capacity ◽  
Comparative Test ◽  
Tensile Failure ◽  
Compressive Failure ◽  
Initial Value ◽  
Short Term ◽  
Glulam Beam ◽  
Flexural Performance ◽  
Creep Characteristics

Due to wood creep characteristics, the failure mode, bearing capacity, stiffness, and deformation of its components are doomed to be impacted by long-term loading. This paper conducted a comparative test on creep beams, regulated beams, and short-term beams based on the former long-term loading research. The results demonstrated that the glulam beam experienced tensile failure of the beam-bottom, while the horizontal joint failure and the local compressive failure of the beam-end happened in the reinforced glulam beam and the prestressed glulam beam. The bearing capacity of the creep beams decreased compared with that of the short-term beams; the decline in the bearing capacity of the ordinary glulam beams, the reinforced glulam beams, and the prestressed glulam beams ranged from 4.22% to 9.83%, from 2.64% to 13.23%, and from 2.90% to 9.16%, respectively. However, the bearing capacity of the regulated beam with the deformation restored to the initial value of the load increased by 4.62–14.08%. The prestressed regulation changed the distribution of the stress on the beam and thus enhanced its bearing capacity. The findings of this work could be used as a frame of reference for similar components in engineering applications.

Design and Research of Double-Drum Winch with Anti-Pressure Wheel

2012 ◽  
Vol 479-481 ◽  
pp. 1709-1713
Author(s):  
Kai An Yu ◽  
Tao Yang ◽  
Chang Zhi Gong
Keyword(s):  
Finite Element ◽  
Bearing Capacity ◽  
Finite Element Methods ◽  
Design Method ◽  
New Method

In view of the problems of large stress and severe bearing heating in double-drum winch at present, this paper adopted a new method to enhance bearing capacity for double-drum winch by adding anti-pressure wheels between two drums. Finite element methods were used to analyze the strength of 4000kN-traction double-drum winches with anti-pressure wheels and without anti-pressure wheels respectively. The results of the analysis revealed that the stress of the cylinder bearing decreased from 264MPa to 167MPa. The new method by adding anti-pressure wheels had remarkably improved the endurance of the bearing. Therefore, the design method can be widely used in large-traction double-drum winch.

Experimental Study about Bearing Capacity and Deformation on Concrete Composite Slabs with Additional Bars

2013 ◽  
Vol 482 ◽  
pp. 7-10
Author(s):  
Jian Hua Cui ◽  
Chuan Yang Weng ◽  
Yun Lin Liu
Keyword(s):  
Experimental Study ◽  
Bearing Capacity ◽  
Failure Mode ◽  
Static Loading ◽  
Flexural Behavior ◽  
Flexural Properties ◽  
Effective Height ◽  
Composite Slabs

Through the experiments of four concrete composite slabs under static loading to compare their flexural properties (deflection, bearing capacity, failure mode), this paper discusses the influence of composite slabs flexural behavior on different length of additional bars and sectional effective height. The results showed that they will improve the bearing capacity effectively by reasonably increasing the sectional effective height and controlling the length of additional bars.

scholarly journals Tests and Analyses of Slotted-In Steel-Plate Connections in Composite Timber Shear Wall Panels

2017 ◽  
Vol 2017 ◽  
pp. 1-20
Author(s):  
Ulf Arne Girhammar ◽  
Bo Källsner
Keyword(s):  
Bearing Capacity ◽  
Failure Modes ◽  
Design Method ◽  
Shear Walls ◽  
Test Results ◽  
Horizontal Shear ◽  
Load Bearing Capacity ◽  
Wood Panel ◽  
Load Bearing ◽  
Plate Connections

The authors present an experimental and analytical study of slotted-in connections for joining walls in the Masonite flexible building (MFB) system. These connections are used for splicing wall elements and for tying down uplifting forces and resisting horizontal shear forces in stabilizing walls. The connection plates are inserted in a perimeter slot in the PlyBoard™ panel (a composite laminated wood panel) and fixed mechanically with screw fasteners. The load-bearing capacity of the slotted-in connection is determined experimentally and derived analytically for different failure modes. The test results show ductile postpeak load-slip characteristics, indicating that a plastic design method can be applied to calculate the horizontal load-bearing capacity of this type of shear walls.

Strength Assessments of Concrete-Filled Steel Tubular Support of Soft Rock Roadway

2013 ◽  
Vol 838-841 ◽  
pp. 1884-1890 ◽  
Author(s):  
Guang Long Qu ◽  
Yan Fa Gao ◽  
Liu Yang ◽  
Bin Jing Xu ◽  
Guo Lei Liu ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Coal Mine ◽  
Soft Rock ◽  
Surrounding Rock ◽  
Flexural Performance ◽  
Laboratory Test Results ◽  
Different Types ◽  
Soft Rock Roadway ◽  
Core Concrete ◽  
Rock Roadway

Compared with I-shaped and U-shaped supports in soft rock roadway, concrete-filled steel tubular (CFST) support, as a new supporting form, has stronger bearing capacity with reasonable price. So it is becoming more and more popular in roadway supporting of coal mine in China. In this article, the surrounding rock in soft rock roadway was classified into three different types: hard rock in deep coal mine, soft surrounding rock, extremely soft surrounding rock. And, according to the characteristics of deformation failure of the CFST support and the surrounding rock in the industrial tests, three different strength assessments, including assessment of axial compressive strength, assessment of lateral flexural performance, assessment of hardening rate of core concrete, were proposed through mechanical analysis and laboratory tests for the three different types of the surrounding rock, respectively. Moreover, aimed to insufficient flexural strength of the support or low hardening rate of the core concrete in some of the roadway supporting, strengthening lateral flexural performance or making early strength concrete was necessary for the above unfavorable situations. The laboratory test results showed that the ultimate bearing capacity for the CFST support with φ194*8mm of steel tube reinforced by φ38mm round steel was 31% greater than that of the unreinforced one, 177% greater than that of the U-shaped one with equivalent weight per unit length.

scholarly journals Steel Plate Cold-Rolled Section Steel Embedded High-Strength Concrete Low-Rise Shear Wall Seismic Performance

2018 ◽  
Vol 2018 ◽  
pp. 1-18
Author(s):  
Min Gan ◽  
Yu Yu ◽  
Liren Li ◽  
Xisheng Lu
Keyword(s):  
Bearing Capacity ◽  
Failure Mode ◽  
Seismic Performance ◽  
High Strength Concrete ◽  
Steel Plate ◽  
Shear Walls ◽  
High Strength ◽  
Shear Wall ◽  
Steel Plates ◽  
Strength Concrete

Four test pieces with different steel plate center-to-center distances and reinforcement ratios are subjected to low-cycle repeat quasistatic loading to optimize properties as failure mode, hysteretic curve, skeleton curve, energy dissipation parameters, strength parameters, and seismic performance of high-strength concrete low-rise shear walls. The embedded steel plates are shown to effectively restrict wall crack propagation, enhance the overall steel ratio, and improve the failure mode of the wall while reducing the degree of brittle failure. Under the same conditions, increasing the spacing between the steel plates in the steel plate concrete shear wall can effectively preserve the horizontal bearing capacity of the shear wall under an ultimate load. The embedded steel plates perform better than concealed bracing in delaying stiffness degeneration in the low-rise shear walls, thus safeguarding their long-term bearing capacity. The results presented here may provide a workable basis for shear wall design optimization.

scholarly journals Uplift Test and Design Method for Bearing Capacity of Isolated Spread Concrete Foundation Slab with Large Width-to-Height Ratio

2018 ◽  
Vol 2018 ◽  
pp. 1-16
Author(s):  
Yuanqi Li ◽  
Xiaoliang Qin ◽  
Jinhui Luo ◽  
Meng Xiao ◽  
Cong Hua
Keyword(s):  
Bearing Capacity ◽  
Design Method ◽  
Numerical Models ◽  
Correction Coefficient ◽  
Uplift Capacity ◽  
Height Ratio ◽  
Foundation Slab ◽  
Concrete Foundation ◽  
Practical Engineering ◽  
Large Width

This paper is focused on the experimental study and numerical simulation of isolated spread concrete foundation slab with a large width-to-height ratio (in short ISCFS-LWR) to investigate the failure modes and uplift bearing capacity, as well as the design method of uplift capacity. First, a total of 16 isolated spread concrete foundation slabs with the width-to-height ratio varied from 1.5 to 4 and the hypotenuse slope varied from 10° to 30° were tested under uplift load. Based on the test results, effects of the width-to-height ratio and the hypotenuse slope on uplift bearing capacity of ISCFS-LWR were analyzed and discussed. Then, several numerical models were built using the finite element software ABAQUS and the results of numerical analysis agreed well with the test results. Furthermore, the cross-sectional performance of ISCFS-LWR was studied, and the coefficients of internal force arm were also evaluated further using previous validated numerical models. To obtain the suggested design method of uplift capacity for the foundation slab, effective width correction coefficient k and slope correction coefficient j were introduced to propose a design formula. Finally, the proposed design method was applied to a practical engineering, and the economic indicators obtained from the suggested design method were compared with that from the original design method. The results of this paper showed that the correction coefficient jsks based on numerical analysis agreed well with the recommended correction coefficient jk, and the error was between 1% and 3.4%, by which the reasonability of the proposed design method of uplift capacity for ISCFS-LWR has been proved. It can also be found that the economic benefits of the practical engineering in this paper were obvious due to the suggested design method, and this paper can provide a reference for other engineering practices and the further research work on ISCFS-LWR.

Experimental Investigation on the Strengthening Composite Beam by Shaped-Steel under R.C Beam Jointed with Short Welding Rebar

2011 ◽  
Vol 250-253 ◽  
pp. 1275-1280
Author(s):  
Li Tang Gao ◽  
Qi Yun Shan ◽  
Tai Wei Wu
Keyword(s):  
Experimental Investigation ◽  
Bearing Capacity ◽  
Failure Mode ◽  
Composite Beam ◽  
Flexural Rigidity ◽  
Detailed Data ◽  
Flexural Capacity ◽  
Investigation Result ◽  
Main Emphasis ◽  
Deformation Behaviors

This paper presents the experimental investigation result from a composite beam strengthened by shaped-steel underpinning (CBSSU) test. There were 3 specimens with one was common R.C beam to compare and others were strengthened by shaped-steel underpinning and jointed with short welding rebars. The main emphasis in undertaking this test was to show the effect of short welding rebars in the strengthening beams and collect more detailed data on the performance of CBSSU such as load capacities, load-deformation behaviors, slipping between shaped-steel and R.C beams, stresses distribution and failure mode. The test shows that the short welding rebars was effective to improve the bearing capacity and stiffness. With limited increase in height of the beam can substantially increase the ultimate flexural capacity and flexural rigidity. The cracks of the beam can also be controlled effectively.

A probabilistic study on the geometrical design of gravity retaining walls

2017 ◽  
Vol 14 (5) ◽  
pp. 414-422 ◽  
Author(s):  
Abdolhosein Haddad ◽  
Danial Rezazadeh Eidgahee ◽  
Hosein Naderpour
Keyword(s):  
Bearing Capacity ◽  
Failure Mode ◽  
Retaining Walls ◽  
Probability Analysis ◽  
Allowable Stress ◽  
Global Mode ◽  
Simple Method ◽  
Content Type ◽  
Mode Of Failure ◽  
Allowable Stress Design

Purpose The purpose of this study is to introduce a relatively simple method of probabilistic analysis on the dimensions of gravity retaining walls which might lead to a more accurate understanding of failure. Considering the wall geometries in the case of allowable stress design, the probability of wall failure is not clearly defined. The available factor of safety may or may not be sufficient for the designed structure because of the inherent uncertainties in the geotechnical parameters. Moreover, two cases of correlated and uncorrelated geotechnical variables are considered to show how they affect the results. Design/methodology/approach This study is based on the failure and stability of gravity retaining walls which can be stated in three different modes of sliding, overturning and the foundation-bearing capacity failure. Each of these modes of failure might occur separately or simultaneously with a corresponding probability. Monte Carlo simulation and Taylor series method as two conventional methods of probability analysis are implemented, and the results of an assumed example are calculated and compared together. Findings The probability analysis of the failure in each mode is calculated separately and a global failure mode is introduced as the occurrence of three modes of sliding, overturning and foundation-bearing capacity failure. Results revealed that the global mode of failure can be used along with the allowable stress design to show the probability of the worst failure condition. Considering the performance and serviceability level of the retaining structure, the global failure mode can be used. Furthermore, the correlation of geotechnical variables seems to be relatively more dominant on the probability of global failure comparing to each mode of failure. Originality/value The introduced terminology of global mode of failure can be used to provide more information and confidence about the design of retaining structures. The resulted graphs maintain a thorough insight to choose the right dimensions based on the required level of safety.

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