scholarly journals Behavior of wood beam connection using staples subjected to in-plane moment

2019 ◽  
Vol 258 ◽  
pp. 05008
Author(s):  
Farida Lenggani ◽  
Bambang Suryoatmono
Keyword(s):  
Failure Mode ◽  
Failure Modes ◽  
Solid Wood ◽  
Experimental Results ◽  
Elastic Analysis ◽  
Connection Strength ◽  
Test Results ◽  
Lateral Resistance ◽  
Wood Beams ◽  
Mechanical Fasteners

It is very frequent that solid wood beams need to be connected one to another to obtain a longer beam. In this study, the behavior of solid wood beams connections using plywood sheets as connecting elements and staples as mechanical fasteners were studied experimentally. The experimental results were compared with elastic analyses. Both beam and plywood were made of meranti (shorea). The staple type was MAX 1022J. This study was conducted on two specimens. The first specimen had two rows of staples on the front and back sides of the specimen. Each row consisted of ten staples making a total of 40 staples. The second one had three rows of staples on the front and back sides of the specimen. Each row consisted of ten staples making a total of 60 staples. From the tests, it can be concluded that each material in the connection, namely wood beam, plywood, and staples, failed. Failure mode of the wood beam was in the form of crack and tear. Failure mode of the plywood was the damage of the plywood directly contacted with the crown of the staples. Failure modes of the staples were flexural yielding. The differences between connection strength obtained from tests and elastic analyses were 8.18% for the first specimen and 0.65% for the second specimen, with the test results were higher than the elastic analyses results. It can be concluded that elastic analysis is quite accurate and conservative to estimate the strength of this type of connection, provided that the lateral resistance of connection with a staple is known.

Design Equations for Preventing Buckling in Fabricated Torispherical Shells Subjected to Internal Pressure

1986 ◽  
Vol 200 (2) ◽  
pp. 127-139 ◽  
Author(s):  
G D Galletly
Keyword(s):  
Internal Pressure ◽  
Failure Mode ◽  
Failure Modes ◽  
Experimental Results ◽  
Design Equation ◽  
Test Results ◽  
Theoretical Predictions ◽  
The Subject ◽  
The Difference ◽  
Empirical Constants

Design rules to prevent buckling in thin fabricated torispherical shells subjected to internal pressure are not yet available in either the American or the British pressure vessel Codes. They are the subject of the present paper and some possible design equations are suggested. The equations were obtained from the buckling equations for perfect torispheres after considering all known experimental results on fabricated models. The empirical constants in the proposed design equations depend on the type of head construction used, i.e. whether crown and segment or pressed and spun. For both types of head the equations give a factor of safety of at least 1.5. The design equation proposed for the crown and segment heads was also checked on several large vessels which had failed in service. The safety factors found for these cases were all greater than 1.7, which means that the vessels would not have buckled if the design equation had been available at the time. The other failure mode of these torispherical heads, i.e. large axisymmetric deformations leading to through-thickness yielding, is also discussed briefly. Curves are given which show that, for 300 < D/t < 500, buckling controls the failure mode in some cases and axisymmetric yielding in others. Neither the American nor the British codes recognize that buckling can occur in this D/t range but the theoretical predictions have been confirmed by experiments. However, the amount of test data is limited and more work is needed on the topic. It is also shown in the paper that, for torispherical shells with D/t ratios in the range 300 < D/t < 500, the axisymmetric limit pressures, pDS, are lower than both the internal buckling pressures and the large deflection axisymmetric yielding pressures. From this, one would expect the failure modes to be axisymmetric in this D/t range. However, as some non-symmetric buckling failures have occurred, the limit analysis predictions for the failure mode are thus not always correct. One feature of the experimental results on stainless steel torispherical shells which are reviewed in the paper is the relatively poor buckling performance of the heads tested by Kemper in comparison with similar heads tested by Stanley and Campbell. As the values of the empirical constants in the design equations are controlled by the lowest test results, the higher bucking pressures obtained by Stanley/Campbell cannot be utilized unless an adequate explanation for the difference in the two sets of results is forthcoming.

Assesment of Main Models for Predicting Debonding Load-Bearing Capacity against Intermediate Crack-Induced Debonding Failure in FRP-Strengthened RC Beams

2011 ◽  
Vol 311-313 ◽  
pp. 1941-1944
Author(s):  
Gui Bing Li ◽  
Yu Gang Guo ◽  
Xiao Yan Sun
Keyword(s):  
Bearing Capacity ◽  
Failure Mode ◽  
Failure Modes ◽  
Rc Beams ◽  
Test Results ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Accuracy Test ◽  
New Models ◽  
Debonding Load

intermediate crack-induced debondingis one of the most dominant failure modes in FRP-strengthened RC beams. Different code models and provisions have been proposed to mitigateintermediate crack-induced debondingfailure.However, these models and provisions can not mitigate this failure mode effectively. Recnetly, new models have been proposed to solve this problem. Out of all the existing models, four typical ones are investigated in the current study. A comprehensivecomparison among these models is carried out in order to evaluate their performance and accuracy. Test results offlexural specimens with intermediate crack-induced debonding failurecollected from the existing literature are used in the current comparison. The effectivenessand accuracy of each model have been evaluated based on these experimental results. It is shown that the current modals are all conservative and inadequite to effectively mitigate intermediate crack-induced debonding in flexurally strengthened members.

A Performance Study on Self-Piercing Riveting and Adhesive Hybrid Joints of Different Adhesive

2014 ◽  
Vol 887-888 ◽  
pp. 1261-1264
Author(s):  
Fu Long Liu ◽  
Xiao Cong He ◽  
Yu Qi Wang
Keyword(s):  
Failure Mechanism ◽  
Energy Absorption ◽  
Failure Mode ◽  
Failure Modes ◽  
Test Results ◽  
Performance Study ◽  
Strength Capacity ◽  
Hybrid Joints ◽  
Overall Performance ◽  
Tension Loading

This paper studied the performance of self-piercing riveting (SPR) and adhesive hybrid joints of different adhesive, including strength, capacity of energy absorption, failure mode and failure mechanism of the hybrid joints. The performances of SPR-adhesive hybrid joints were compared with SPR joints. SPR-adhesive hybrid joints and SPR joints were tested under a tension loading. The test results showed that adhesive have a function of improving the strength of SPR joints; however, the capacity of energy absorption of SPR joints was weakened. While the adhesive have no effect on the failure modes of SPR joints. When appropriate adhesive was selected, the overall performance of SPR-adhesive hybrid joints was superior to SPR joints. In a word, the combination of SPR and adhesive could get a well jointing structure.

Behaviour of adhesive steel anchors under impulse-type loading

2009 ◽  
Vol 36 (11) ◽  
pp. 1835-1847 ◽  
Author(s):  
Abass Braimah ◽  
Ettore Contestabile ◽  
Rick Guilbeault
Keyword(s):  
Failure Mode ◽  
Failure Modes ◽  
Dynamic Behaviour ◽  
Stone Masonry ◽  
Experimental Program ◽  
Embedment Depth ◽  
Test Results ◽  
Dynamic Increase Factor ◽  
Adhesive Anchors

The dynamic behaviour of adhesive anchors embedded in concrete is not well established, neither is their behaviour in stone masonry. This paper presents an experimental program designed to study the dynamic behaviour of adhesive anchor – substrate systems under impulse-type loading. The adhesive anchor – substrate systems consisted of steel rods bonded to concrete and limestone with an epoxy-based adhesive. Two steel anchor diameters (6.4 and 9.5 mm), two embedment depths (89 and 114 mm), and two angles of substrate penetration (90° and 45°) were investigated. The predominant failure mode observed for the steel anchor – concrete substrate samples was steel fracture, whereas for the steel anchor – limestone substrate samples, both steel fracture and limestone substrate failure modes were observed. The test results show that in most cases the dynamic increase factor (DIF) of adhesive anchors decreases with an increase in the embedment depth. Also, a substrate penetration angle of 45° increases the DIF in comparison with samples with 90° penetration angle. The DIFs of 1.2 and 2.5 are recommended for adhesive anchors with normal and 45° limestone substrate penetrations, respectively, while for concrete substrate, the recommended DIFs are 1.2 and 3.2 for normal and 45° substrate penetrations, respectively.

Influence of Rubber Content on Failure Mode and Resistance Characteristics of PC/ABS Blends and their ABS Constituents under Impact

2021 ◽  
Vol 892 ◽  
pp. 67-73
Author(s):  
Muhammad Nizar Machmud ◽  
Masaki Omiya ◽  
Hirotsugu Inoue ◽  
Kikuo Kishimoto
Keyword(s):  
Impact Toughness ◽  
Impact Strength ◽  
Failure Mode ◽  
Room Temperature ◽  
Failure Modes ◽  
Impact Test ◽  
Rubber Particle ◽  
Test Results ◽  
Rubber Content ◽  
Particle Content

This present study has been re-established to investigate failure mode and resistance characteristics of the PC/ABS blends and their ABS constituents under impact for a range of rubber contents. This present study has still been experimentally performed under an instrumented-drop weight impact test (DWIT) at a room temperature. It has been finally revealed that with a particular size of rubber particle, content of rubber significantly influenced impact failure modes and impact resistances of the PC/ABS blends and their ABS constituents as well. The test results showed that impact strength of the blends was improved about 23.22% and 155.33% due to increase in content of rubber up to 15 wt% and 20 wt%, respectively. There was also found that an increase in impact toughness of the blends for 57.48% and 239.23% was due to increase in content of rubber up to 15 wt% and 20 wt%, respectively. Whilst, impact strength of the ABS was improved about 392.98% and 190.12% due to increase in content of rubber up to 15 wt% and 20 wt%, respectively. An increase in impact toughness of the ABS for 308.20% and 172.56% was due to increase in content of rubber up to 15 wt% and 20 wt%, respectively.

Evaluation of Main Code Models for Predicting Flexural Load-Bearing Capacity against Intermediate Crack-Induced Debonding in FRP-Strengthened RC Beams

2011 ◽  
Vol 71-78 ◽  
pp. 1465-1468
Author(s):  
Gui Bing Li ◽  
Yu Gang Guo ◽  
Xiao Yan Sun
Keyword(s):  
Bearing Capacity ◽  
Failure Modes ◽  
Experimental Results ◽  
Rc Beams ◽  
Test Results ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Accuracy Test ◽  
Comprehensive Comparison ◽  
Code Provisions

Intermediate crack-induced debonding is one of the most dominant failure modes in FRP-strengthened RC beams. Different code models and provisions have been proposed to predict intermediate crack-induced debonding failure. Out of all the existing code provisions and models, four typical ones are investigated in the current study. A comprehensive comparison among these code provisions and models is carried out in order to evaluate their performance and accuracy. Test results of flexural specimens with intermediate crack-induced debonding failure collected from the existing literature are used in the current comparison. The effectiveness and accuracy of each model have been evaluated based on these experimental results. It is shown that the current recommendations are inadequite to effectively mitigate intermediate crack-induced debonding in flexurally strengthened members.

Experimental Study on Seismic Failure Modes of Confined Masonry Structures with Different Enhancements

2017 ◽  
Vol 747 ◽  
pp. 594-603 ◽  
Author(s):  
Hu Xu ◽  
Hao Wu ◽  
Cristina Gentilini ◽  
Qi Wang Su ◽  
Shi Chun Zhao
Keyword(s):  
Experimental Study ◽  
Failure Mode ◽  
Seismic Behavior ◽  
Failure Modes ◽  
Experimental Results ◽  
Masonry Walls ◽  
Masonry Structures ◽  
Structural Collapse ◽  
Static Loads ◽  
Confined Masonry

In this study, confined masonry specimens with regular arranged openings are tested in order to study the influence of different enhancements of the columns on seismic failure modes. In particular, five brick masonry walls and three half-scale two-storey masonry structures are tested under quasi-static loads. The experimental results show that increasing column ratio improves the seismic behavior of the wall specimens to some extent, but an excessive reinforcement ratio of the columns decreases the ductility. The global failure mode of the two-storey masonry structures is modified by inserting iron wires in the mortar bed joints, improving the structural collapse resistant capacity effectively.

Fracture Model for PT Flat Plate Connections under Seismic Loading

2008 ◽  
Vol 385-387 ◽  
pp. 709-712
Author(s):  
Ki Hoon Moon ◽  
Hwang Bo Jin ◽  
Sang Whan Han
Keyword(s):  
Flat Plate ◽  
Failure Mode ◽  
Analytical Model ◽  
Failure Modes ◽  
Nonlinear Behavior ◽  
Shaking Table ◽  
Cyclic Behavior ◽  
Test Results ◽  
Seismic Regions ◽  
Plate Connections

Post-tensioned (PT) flat plate frames are commonly used to support gravity load in connections in high seismic regions. But test results of many studies indicated that PT flat plate connections were possessed of later-resisting capacity for lateral load though this capacity is not enough to be used by itself in high seismic regions. So this study evaluated the cyclic behavior of PT flat plate connections and developed an analytical model for predicting nonlinear behavior of those to estimate the seismic performance of PT flat plate frames accurately. For this purpose, the test results of static pushover test and shaking table test of 2 story PT flat plate frame were used to evaluate the characters of failure mode for PT flat plate connections and to compare with analysis results. The test results indicated two failure modes which are classified the shear failure mode or the moment failure mode as for shear strength of PT connections to resist lateral loads acted on the specimens. So the analytical model was designed to consider these failure modes of PT connections and the results of comparing with test results predict the nonlinear behavior of PT connections.

Theoretical and experimental considerations on the neutral axis of wood beams with a hole in different locations

Holzforschung ◽  
2018 ◽  
Vol 72 (9) ◽  
pp. 769-777
Author(s):  
Yuxin Wen ◽  
Ping Yang ◽  
Jian Zhao ◽  
Dong Zhao
Keyword(s):  
Solid Wood ◽  
Neutral Axis ◽  
Experimental Results ◽  
Image Correlation ◽  
Plastic Behavior ◽  
Tension Zone ◽  
Compression Zone ◽  
Four Point Bending ◽  
Wood Beams ◽  
Dic Technique

AbstractHoles contribute to the non-homogeneous nature of solid wood and shift the neutral axis of wood beams away from the centroid. Based on the plane-section assumption and idealized trapezoidal distribution, new calculating formulas will be presented in terms of the location of neutral axis for clear beams and wood beams with a hole at the center, compression zone and tension zone. To verify the results of theoretical analysis and formulas, four-point bending experiments of wood beams were performed by a digital image correlation (DIC) technique. There is a reasonable agreement between calculated and experimental results with a hole at the center or in the compression zone of the beams. Concerning a hole in the tension zone, on the other hand, the calculated locations of neutral axis are not in agreement with the experimental results, due to the plastic behavior on both the compression and tension zones of the beams in the inelastic stage.

scholarly journals Experimental and Numerical Analysis of Hollow and Solid Reinforced Concrete Piers under Static and Impact Loadings

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Pengfei Yao ◽  
Junyu Zhu ◽  
Lu Zhu ◽  
Hai Fang ◽  
Changgen Qian
Keyword(s):  
Reinforced Concrete ◽  
Failure Mode ◽  
Failure Modes ◽  
Impact Force ◽  
Impact Load ◽  
Experimental Results ◽  
Impact Behavior ◽  
Low Velocity ◽  
Process Failure ◽  
Damage Process

Collision on reinforced concrete (RC) piers by moving vessels or vehicles is a significant issue. This paper presents the static and impact behavior of RC piers with different hollow ratios. Three specimens were statically tested to obtain the load-displacement response. Low-velocity collision on eleven RC piers was conducted under the same velocity of 2.42 m/s. The damage process, failure mode, and force response were comprehensively analyzed. The experimental results indicate that the hollow ratio plays a significant role in the failure mode and ultimate load of RC piers under static and impact loadings. For RC piers with a hollow ratio of 0 and 0.4, the global failure dominated the damage process. However, failure of piers with a hollow ratio of 0.6 was governed by the local damage near the loading point. The static load capacities of the RC piers with a hollow ratio of 0.4 and 0.6 were 1.27% and 60.5% smaller than that of the solid pier, respectively. RC piers with a higher hollow ratio or lighter drop weight suffer smaller peak impact force. The increase of the longitudinal reinforcements leads to a promotion of the peak and mean impact force. Furthermore, the numerically predicted failure modes and impact load response show satisfactory agreement with the experimental results.

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