scholarly journals Effects of decay on the shear properties of nailed joints parallel and perpendicular to the grain

2021 ◽  
Vol 67 (1) ◽  
Author(s):  
Rintaro Ueda ◽  
Kei Sawata ◽  
Takanobu Sasaki ◽  
Yoshihisa Sasaki
Keyword(s):  
Penetration Depth ◽  
Initial Stiffness ◽  
Shear Properties ◽  
Maximum Resistance ◽  
Loading Direction ◽  
Low Load ◽  
Timber Constructions ◽  
Pilodyn Penetration ◽  
Loading Tests ◽  
The Relationship

AbstractInformation on the properties of nailed joints with decayed member is necessary to evaluate the remaining structural properties of timber constructions. In this study, loading tests were conducted on nailed joints parallel and perpendicular to the grain with decayed members, and the relationship between the decrease in shear properties and the loading direction to the grain was investigated. After the loading tests, the extent of decay of the specimens was evaluated by the penetration depth of Pilodyn and the decay depth, and these were compared with the shear properties of the nailed joints. The nailed joints with decay had a low load at the initial deformation, regardless of the loading direction to the grain. The initial stiffness, yield resistance, and maximum resistance of the nailed joints parallel to the grain were negatively correlated with the Pilodyn penetration depth, and those of the nailed joints perpendicular to the grain showed no significant correlation with the Pilodyn penetration depth at the 5% level. The initial stiffness, yield resistance, and maximum resistance of the nailed joints parallel to the grain tended to decrease with increasing decay depth, and those of the nailed joints perpendicular to the grain did not exhibit this tendency. The shear properties of the nailed joints significantly decreased at small decay depths.

Experimental Investigation on Rotary Punching by the Compression of Polyurethane Pad

2014 ◽  
Vol 941-944 ◽  
pp. 1802-1807 ◽  
Author(s):  
Qian Liu ◽  
Jing Tao Han ◽  
Jing Liu ◽  
Xiao Xiong Wang
Keyword(s):  
Penetration Depth ◽  
Process Parameters ◽  
High Load ◽  
Large Area ◽  
Bear Capacity ◽  
Hole Edge ◽  
Quality Degradation ◽  
Series Of Experiments ◽  
Blanking Process ◽  
The Relationship

Rotary punching is a sheet metal blanking process which utilizes shearing tools fixed to a pair of rollers. The polyurethane pad is adopted as the die instead of rigid mold because it has the advantages of wide hardness range and high load-bear capacity. Due to the application of polyurethane pad, the surrounding region adjacent to the pierced hole will occur to plastically deform and deflect, which greatly differs from that in the conventional blanking. In this paper, the effects of blank material and thickness, polyurethane hardness, punch penetration depth on deformation behavior were mathematically analyzed and modeled, and then a series of experiments through varying process parameters were conducted to validate the relationship between process parameters and product quality. The degree of sample deflection was exactly measured by scanning electron microscope (SEM). The results show that the deformed area varies with different blank elongations and increases with increasing blank thickness for a given material. When polyurethane pad with low hardness level is employed, it results in large area deformation and quality degradation. Moreover, the deflection degree around the hole edge becomes more severe along with punch penetration, but the penetration depth along blank thickness is not in proportion to the amount of punch advancement.

scholarly journals Relationship between Growth and Wood properties in Agathis sp. Planted in Indonesia

2017 ◽  
Vol 3 (1) ◽  
pp. 1-5
Author(s):  
Futoshi Ishiguri ◽  
Kazuko Makino ◽  
Imam Wahyudi ◽  
Jun Tanabe ◽  
Yuya Takashima ◽  
...  
Keyword(s):  
Wood Quality ◽  
Basic Density ◽  
Tree Breeding ◽  
Wood Properties ◽  
Stem Diameter ◽  
Breeding Programs ◽  
Significant Difference ◽  
Pilodyn Penetration ◽  
The Mean ◽  
The Relationship

The present study clarified the relationship between the growth and wood properties of 54-year-old Agathis sp. trees planted in Indonesia. Stem diameter, pilodyn penetration, and stress-wave velocity (SWV) were measured for all trees (35 trees) in a plot (30  30 m) located almost at the center of a stand. Based on the mean stem diameter, 10 standard trees in a plot were selected for measuring the basic density (BD) and compressive strength parallel to grain (CS). Core samples (5 mm in diameter) were collected from the 10 selected trees to determine BD and CS. The mean stem diameter, pilodyn penetration and SWV in the plot were 40.2  11.3 cm, 23.4  2.1 cm, and 3.85  0.43 km/s, respectively. No  significant correlation coefficeint (r = -0.327, no significance at 5% level) was obtained between stem diameter and SWV. The mean BD and CS in the 10 trees were 0.42  0.03 g/cm3  and 28.1  2.7 MPa, respectively. A significant positive  correlation was observed between BD and CS. Analysis of variance (ANOVA) revealed a significant difference between BD and CS values of the 10 trees, indicating that wood properties may differ among trees with the same standard growth in a stand. From these results, we concluded that wood quality improvement in this species could be achieved by selecting  trees with high density and strength in tree breeding programs.

scholarly journals Studi Eksperimental: Perilaku Siklik Anticompression Split-K Braced Steel Frame

2020 ◽  
Vol 14 (2) ◽  
pp. 143-153
Author(s):  
Oksa Eberly ◽  
◽  
Sri Murni Dewi ◽  
Wisnumurti Wisnumurti ◽  
◽  
...  
Keyword(s):  
Steel Frames ◽  
Cyclic Strength ◽  
Steel Frame ◽  
Lateral Loads ◽  
Cyclic Tests ◽  
Initial Stiffness ◽  
Loading Tests ◽  
Quasistatic Loading ◽  
Cyclic Loading Tests ◽  
Good Behaviour

This paper presents an experimental study on the behaviour of a braced steel frame with a proposed system: anticompression brace system (ABS) subjected to cyclic lateral loads. The ABS is proposed to deal with common brace buckling problems. In the study, split-K braced steel frames: with ABS and with ordinary brace system (OBS) were used as speciments. Cyclic loading tests were conducted to evaluate the performance of the proposed system in preventing the brace to buckle and to obtain the behaviour of the frame with ABS compared to the frame with OBS under cyclic quasistatic loading. From the cyclic tests, it was observed that the proposed system worked in preventing the braces to buckle, hence, the aimed state, “buckling prevention” was achieved. The results of the study also show that the frame with ABS had a lower initial stiffness compared to the frame with OBS, nevertheless, after exceeding drift ratio of 0.85% based on raw data or 0.64% based on fitted-curves, the frame with ABS exhibited good behaviour through lower degradations in stiffness and cyclic strength relative to the frame with OBS that experienced sudden and greater degradations.

scholarly journals Buried Depth of a Submarine Pipeline Based on Anchor Penetration

2019 ◽  
Vol 7 (8) ◽  
pp. 257
Author(s):  
Xueyuan Zhu ◽  
Qinglong Hao ◽  
Jie Zhang
Keyword(s):  
Numerical Simulation ◽  
Penetration Depth ◽  
Water Depth ◽  
Calculation Method ◽  
Water Surface ◽  
Submarine Pipeline ◽  
Projected Area ◽  
Actual Measurement ◽  
Calculation Results ◽  
The Relationship

Anchor penetration is an important issue involved in the study of submarine pipeline damage accidents. To explore the penetration of a ship’s anchor under certain conditions, this study investigated the motion and force of an anchor and formulated a calculation method for the bottoming speed of an anchor. Meanwhile, the depth of anchor penetration was calculated under different conditions according to bottoming speed through programming. Finally, the reliability of the calculation method for the penetration depth was verified by comparing the actual measurement and the numerical simulation. On the basis of the findings, the calculation results were further analyzed, and conclusions were derived regarding the relationship between anchor mass, the horizontal projected area of the anchor, the anchor height on the water surface, and water depth. The conclusions provide suggestions for the application of anchor penetration in terms of seabed depth with certain reference values.

The Numerical Simulations of Forces Acting on TBM Disc Cutters with the Consideration of Confining Pressure and Damage in Rocks

2011 ◽  
Vol 105-107 ◽  
pp. 1170-1174
Author(s):  
Hui Yun Li ◽  
Guang Yu Shi
Keyword(s):  
Penetration Depth ◽  
Cutting Forces ◽  
Confining Pressure ◽  
Material Model ◽  
Disc Cutter ◽  
Finite Element Software ◽  
Linear Dynamic ◽  
Dynamic Finite Element ◽  
Disc Cutters ◽  
The Relationship

This paper gives a brief explanation of the failure mechanism of rock fragmentation in rock cutting. The JOHNSON_HOLMGIST_CONCRETE is selected as the rock material model in numerical simulation with confining pressure and damage influence introduced. We use the non-linear dynamic finite element software LS/DYNA to simulate the dynamic process of cutting rock. The cutting forces acting on disc cutter are computed. The relationship between cutting forces and penetration depth, confining pressure and damage parameters are obtained. The results show that, the cutting forces increase with the penetration depth. They are larger in equal confining pressure than unequal condition. The forces are amplified with the damage parameters increasing. The conclusion provides a reference for the prediction of the cutting forces.

Study on Corner Contact Shock of Gear Transmission by ADAMS Software

2015 ◽  
Vol 778 ◽  
pp. 205-211
Author(s):  
Li He ◽  
Jin Yuan Tang
Keyword(s):  
Penetration Depth ◽  
Impact Velocity ◽  
Impact Force ◽  
Ansys Software ◽  
New Approach ◽  
Adams Software ◽  
Simulation Results ◽  
The Impact ◽  
The Relationship ◽  
Key Parameter

Solving gear meshing impact force problems by using ADAMS software is studied.A pair of tooth meshing model is established based on UG, modal neutral file is generated by using ANSYS software, calculating gear meshing impact after Importing ADAMS. The relationship between the impact velocity and the impact force by taking reasonable key parameter about penetration depth in ADAMS simulation.A new approach for studying gear meshing impact is proposed here, and the simulation results show that ADAMS software is a very useful tool for solving gear corner contact shock problems outside the normal path of action line.

Effect of Aggregate Volume Fraction on the Charge Passed of Mortar and Concrete

2009 ◽  
Vol 405-406 ◽  
pp. 283-288 ◽  
Author(s):  
Quan Lin Niu ◽  
Chong Zhi Li
Keyword(s):  
Penetration Depth ◽  
Volume Fraction ◽  
Low Permeability ◽  
Chloride Permeability ◽  
Volume Fractions ◽  
Aggregate Fraction ◽  
Low Charge ◽  
Astm C1202 ◽  
The Relationship ◽  
Cl Permeability

Charge passed of mortars with different aggregate volume fractions was tested according to ASTM C1202, and the differential expression of the Ohm law was introduced to explain the relationship between charge passed data and aggregate fractions.Cl- penetration depth of the corresponding mortars and concretes was measured to illustrate the influence of the aggregate volume fraction on their chloride permeability. It was shown that the charge passed of mortar was negatively correlated with aggregate volume fractions, and high aggregate fraction bearing concrete with low charge passed did not necessarily mean low permeability. As a result, the influence of aggregate fraction on charge passed should be taken into consideration when charge passed data was employed to evaluate Cl- permeability of concrete.

Study on the Displacement Characteristic of Uplift Anchor under Cyclic Loading

2011 ◽  
Vol 243-249 ◽  
pp. 2965-2968
Author(s):  
Zhong Miao Zhang ◽  
Nian Wu Liu ◽  
Kai Fang ◽  
Qian Qing Zhang
Keyword(s):  
Cyclic Loading ◽  
Effective Length ◽  
Peak Loads ◽  
Anchor Length ◽  
Loading Tests ◽  
Cyclic Loading Tests ◽  
The Relationship

This paper presents the results of the cyclic loading tests for 30 uplift anchors. The relationship between the loads and displacements for each anchor under cyclic loading is studied and the results show that the behavior of the anchor is largely influenced by its length. It is common for the Q-S curves of different anchors to vary quite widely. The displacements under different load levels decrease with increasing anchor length but the decreasing rate has a number of variations. It is also found that the final displacements of the anchors are dominated by plastic displacements which positively correlated with the peak loads. In addition, the effective length of the anchor is related to the load acted on it.

Study on the Traffic Capacity of Expressway Based on Cellular Automata Model

2014 ◽  
Vol 701-702 ◽  
pp. 172-179
Author(s):  
Xiao Dong Xia ◽  
Lin Ling Xu
Keyword(s):  
Cellular Automata ◽  
Traffic Flow ◽  
Heavy Traffic ◽  
Accident Rate ◽  
Cellular Automata Model ◽  
Traffic Capacity ◽  
Low Load ◽  
The Right ◽  
The Relationship ◽  
Shape Changes

Based on the Nagel-Schrekenberg cellular automaton model of traffic flow, this article analyzed the influence that driving on the right side takes to the traffic flow in the condition of light and heavy traffic. With the combination of fluid dynamics and vehicle dynamics, we established the Cellular Automata model for mixed speed two-lane traffic flow on the rule driving on the right side. Then we used the AHP method to find out the large bus share rate, the number of vehicles changing lanes and the influence law of safety factors on traffic flow. We came to a conclusion that the relationship between traffic flow and load are inverted U shape changes in the low load and high load conditions, the accident rate is the maximum when the V/C (the ratio of traffic flow and the ability of corresponding section) is the minimum; with the increase of V/C, the accident rate decreased gradually.

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