Stability Analyses of the Upper Chord Tubes of Light Gauge Steel–Oriented Strand Board Composite Truss Girders

2016 ◽  
Vol 16 (01) ◽  
pp. 1640012 ◽  
Author(s):  
Lanying Zhu ◽  
Yuanzhang Yang ◽  
Zhijun Wang ◽  
Mengli Song
Keyword(s):  
Failure Mode ◽  
Static Loading ◽  
Oriented Strand Board ◽  
Local Buckling ◽  
Experimental Tests ◽  
Test Results ◽  
Number Of Layers ◽  
Simulation Results ◽  
The Stability ◽  
Composite Girders

Light Gauge Steel (LGS) square tube truss girders with Oriented Strand Board (OSB) have larger bending stiffness and flexural capacities than the LGS square tube girders without OSB. In this paper, one LGS square tube truss girder without OSB and five composite LGS truss girders with OSB were tested under monotonic static loading to study the effects of OSB arrangements and screw distributions on the failure mode and flexural capacities of composite girders. Test results show that the failure mode of LGS–OSB composite truss girders tends to be local buckling of the upper chord tubes, and the ultimate bearing capacities of the composite girders are controlled by the stability of the upper chord tubes. LGS–OSB composite truss girders have higher bearing capacities than the truss girders without OSB. The thicker the OSB is, the larger the bearing capacity is. With the same OSB thickness, the number of layers and the orientation of OSB have little influence on the bearing capacities of LGS–OSB composite truss girders. Considering material, geometry and contact nonlinearities, the experimental tests were simulated using ABAQUS, and the simulation results agree well with the test observations. Finally, in order to obtain the ultimate bearing capacities of LGS–OSB composite truss girders, the modified methods for determining the effective areas and inertia moments (or sectional moduli) of the upper chord tube are proposed according to AISI S100-2007 and GB50018-2002.

scholarly journals Theoretical Analysis for Local Buckling of Corrugated Steel Plate

2018 ◽  
Vol 38 ◽  
pp. 03002
Author(s):  
Bai Jian Li ◽  
Liang Sheng Zhu ◽  
Xin Sha Fu
Keyword(s):  
Bearing Capacity ◽  
Steel Plate ◽  
Local Buckling ◽  
Experimental Tests ◽  
Material Strength ◽  
Calculation Formula ◽  
Bending Stress ◽  
Test Results ◽  
Concentrated Loads ◽  
Rigid Frame

To study local buckling of Corrugated Steel Plate under concentrated loads. Through experimental tests and theorical analysis, bearing capacity and failure form of Corrugated Steel Plate were discussed. Bearing capacity of Corrugated Steel Plate associated with local buckling, which can be assumed to be composed of three parts: buckling of plane rigid frame caused by concentrated loads, buckling of roof and web caused by bending stress. These three parts were unified by buckling relevant equations, then local buckling calculation formula was obtained. Comparing with experimental results, the loads obtained by local buckling calculation formula agree with test results very well. Since the buckling calculation is independent of the material strength, the calculation formula of local buckling is reliable, it can be used to evaluate local buckling of Corrugated Steel Plate.

Design of the Splitting and Taking Pest Machine

2014 ◽  
Vol 543-547 ◽  
pp. 253-257
Author(s):  
Li Ping Wang ◽  
Yi Guo ◽  
Gang Fu ◽  
Jiang Hui Dong
Keyword(s):  
Simple Structure ◽  
Plant Protection ◽  
Research Work ◽  
The Self ◽  
Motion Simulation ◽  
Test Results ◽  
Simulation Results ◽  
The Stability ◽  
Wear Condition ◽  
Dangerous Section

In order to meet the requirement of splitting wood to take out the pests in the plant protection research work, the splitting and taking pest machine is designed, which working mode is based on spiral transmission. According to the wear condition, the main structure parameters of the spiral transmission device for splitting were determined. Furthermore, the strength of the dangerous section of screw rod, the strength of nuts' teeth, the self-lock of spiral pair and the stability of screw rod were checked. The virtual prototype of splitting and taking pest machine is made by using SolidWorks software, the motion simulation results show that no interference among the various parts. The test results of the prototype indicate that the machine can meet the job requirement to split wood and take out the pests. In addition, the machine has many features, such as simple structure, working smoothly and low vibration.

scholarly journals RESEARCH OF EFFECTS OF DEFECTS ON STABILITY FAILURES OF SEMI-MONOCOQUE STIFFENERS

Aviation ◽  
2020 ◽  
Vol 23 (3) ◽  
pp. 83-90
Author(s):  
Tomáš Katrňák ◽  
Jaroslav Juračka ◽  
Ivo Jebáček
Keyword(s):  
Fe Simulation ◽  
Local Buckling ◽  
Experimental Tests ◽  
Nonlinear Finite Element ◽  
Design Parameters ◽  
Local Mode ◽  
Single Node ◽  
Sudden Failure ◽  
Simulation Results ◽  
Validation Of Results

This article presents further results of the research of effects of model defects on the local buckling of compressed stiffeners in nonlinear finite element (FE) analyses. The main outcomes are confirmation of trends for 10 sets of profile dimensions, final validations of various sets of FE simulations, and designs of practical types of defects with appropriate ratio values. A single node defect and then complex types of defects with alternating distributions of node shifts along one edge, two free flange edges, one flange surface and both flange surfaces are analyzed in this research project. First parts of this paper describe designed FE models with defects, their effects on simulation results, colored graphic visualizations with stress scales and determinations of the sudden failure of stability in the local mode. Then, particular results of FE analyses are validated by a comparison with the results of analytical methods of stability failure. Final detail comparisons of analytical and FE simulation results with data of experimental tests confirm predicted critical buckling forces. The validation of results and design parameters together with the knowledge of effects of model defects on buckling behaviors allows more accurate simulations of internal stiffeners of thin-walled semi-monocoque structures.

Numerical Simulation and Experimental Validation of Frequency Based Fault Detection and Localization in a Planetary Gearbox Under Dynamic Condition

2019 ◽  
Author(s):  
Nithin Venkataram ◽  
Harish K. Bhagavan ◽  
Rahul M. Cadambi ◽  
Arun R. Rao
Keyword(s):  
Numerical Simulation ◽  
Frequency Domain ◽  
Experimental Validation ◽  
Working Condition ◽  
Dynamic Condition ◽  
Experimental Tests ◽  
Test Results ◽  
Planetary Gearbox ◽  
Simulation Results ◽  
Detection And Localization

Abstract The planetary gearbox is often susceptible to faults under dynamic condition. Most of the literature assumes that gearboxes are free from defects. But in real-time working condition these assumptions are not accurate. Therefore the challenge lies in identifying and localizing a fault in planetary gearbox under dynamic condition. In this paper, the focus is on modelling and simulation of a fault in a planetary gearbox and validate the same with experimental tests. A planetary gearbox is modelled as per DIN standard and simulated for time and frequency domain signals. On comparing a fault free and fault induced frequency domain signals, a small peaks are observed on either side of the mesh frequencies, indicating the presence of a fault in the planetary gearbox. These peaks around the mesh frequencies are used to localize the fault in a planetary gearbox. Simulation results are validated with the experimental test results of the planetary gearbox under dynamic conditions. Similar trend is observed in simulation and experimental results.

scholarly journals ANALISIS STABILITAS LONGSORAN BERDASARKAN KONDISI TIPE, SIFAT FISIK DAN MEKANIK BATUAN DI KECAMATAN TELUKPANDAN KABUPATEN KUTAI TIMUR, PROVINSI KALIMANTAN TIMUR.

1970 ◽  
Vol 16 (1) ◽  
Author(s):  
Sujiman Sujiman
Keyword(s):  
Slope Stability ◽  
Rock Mechanics ◽  
Friction Angle ◽  
Research Area ◽  
Test Results ◽  
East Kalimantan ◽  
Overall Stability ◽  
Simulation Results ◽  
The Stability ◽  
Rock Lithology

The research title is Slope Stability Analysis Based On Type, Physical And MechanicalProperties Rock In Teluk Pandan District, East Kutai Regency, East Kalimantan Provinceaimed to determine the lithology in the    research area and to find out how the amount ofslope that will be a landslide at that location.How the research with the analysis of coring drilling results are then analyzed in thelaboratory of rock mechanics to get the caracteristic of physical and mechanical propertiesof the rocks. Methods of data analysis using Hoek and bray methode with Rockslide software.The results showed that in the area study has a sedimentary rock lithology fine tomedium dedritus, such as claystone, siltstone and sandstone, as well as inserts are coal andshale. Based on the results of laboratory analysis of rock mechanics obtained density between2,648 to 2,770. While the test results obtained value triaxal cohesion between (6.66 - 9:05)Kg / cm2, friction angle in between (37.19 - 44.08)o, cohesion residual (2.72 - 3.10) Kg / cm,residual friction angle (27.22 - 32.44). While the direct shear test the cohesion of thesummit between (6.66 - 9:05) Kg / cm2o, friction angle in the cohesion peak (36.15 - 43.00),cohesion residual (2:22 to 3:10) Kg / cm, friction angle in the cohesion residual (37.22 33.85)o2. The simulation results stability of the slope stability Hoek and Bray using rockslidesoftware, the result is that if the slope with a single slope stability, the stability of the slopeis 60o, and if the slope with the stability of the slope overall stability of the slope is 48o.

Application of Compressive Strain Capacity Models to Multiple Grades of Pipelines

2014 ◽  
Author(s):  
Zhenyong Zhang ◽  
Zhifeng Yu ◽  
Ming Liu ◽  
Kunal Kotian ◽  
Fan Zhang
Keyword(s):  
Compressive Strain ◽  
Local Buckling ◽  
High Strength ◽  
Experimental Tests ◽  
Test Results ◽  
Longitudinal Compression ◽  
Experimental Database ◽  
Strain Capacity ◽  
Testing Data ◽  
Experimental And Numerical Modeling

Local buckling due to excessive compressive strain generated by bending and/or longitudinal compression is one of the main threats to pipeline integrity. Strain-based design and assessment (SBDA) methods have been developed for designing and maintaining pipelines under high longitudinal strain. In SBDA, the resistance to local buckling is often measured by compressive strain capacity. Extensive work has been performed on the compressive strain capacity of pipes through both experimental and numerical modeling. Models for calculating the compressive strain capacity have been developed over many decades. Some earlier models were developed using experimental test data of low strength linepipes. High strength linepipes are being increasingly used for the construction of new pipelines. The applicability of the existing models to modern high strength pipelines needs to be evaluated. In this paper, selected compressive strain capacity models were reviewed and evaluated. An experimental database of 61 experimental tests from public-domain publications was created. Approximately 34% of the testing data are from high strength pipes (primarily X80). The calculated compressive strain capacity from the selected models was compared with the test results. The performance of the selected models was evaluated and the applicability of the models to the linepipes of different strengths was discussed.

scholarly journals Shear Behavior of Concrete Encased Steel Truss Composite Girders

2021 ◽  
Vol 11 (4) ◽  
pp. 1569
Author(s):  
Chisung Lim ◽  
Seung-Ho Choi ◽  
Jae Yuel Oh ◽  
Sun-Jin Han ◽  
Moon-Sung Lee ◽  
...  
Keyword(s):  
Shear Failure ◽  
Experimental Tests ◽  
Crack Pattern ◽  
Test Results ◽  
Horizontal Shear ◽  
Failure Plane ◽  
Steel Truss ◽  
Shear Performance ◽  
Shear Cracking ◽  
Composite Girders

In this study, experimental tests were performed to evaluate the shear performance of encased steel truss (EST) composite girders that can resist loads at construction and composite stages. Four full-scale EST composite girders were fabricated, where the truss type (Pratt truss and Warren truss) and presence of stirrups were set as main test variables. The test results showed that in specimens applied with the Pratt truss, horizontal shear cracking occurring along the interface between concrete and steel was the dominant failure mode. Based on the crack pattern and failure plane observed from the test, the horizontal shear strengths of the Pratt truss specimens were calculated, which provided conservative results. On the other hand, in the specimens with the Warren truss inside, the strengths of the specimens were governed by the shear failure occurring in the screw rod connecting the truss elements prior to the yielding of the diagonal member. The shear strengths of the Warren truss specimens calculated based on the shear failure of the screw rod were similar to that obtained from the test.

Numerical and Experimental Study of Natural Backfill of Pipeline in a Trench Under Steady Currents

2010 ◽  
Author(s):  
Di Wu ◽  
Liang Cheng ◽  
Ming Zhao ◽  
Yongxue Wang
Keyword(s):  
Early Stage ◽  
Experimental Tests ◽  
Numerical Results ◽  
Test Results ◽  
Steady Current ◽  
Reference Concentration ◽  
Sea Bed ◽  
Navigation Channel ◽  
The Stability ◽  
Bed Scour

After a sub-sea pipeline is laid in a trench excavated on a sandy sea bed, the sand around the trench will be washed into the trench by the flow, leading to natural backfill. Natural backfill is beneficial to the stability of the pipeline and cost saving. In this study, natural backfill of pipeline trench under steady currents was investigated experimentally and numerically. Experimental tests were carried out in a water flume of a size of 0.4 m in width, 0.6 m in height and 25 m in length. The model pipeline with a diameter of 5 cm was placed in a V-shape trench. The direction of steady current was perpendicular to the pipeline. Tests were carried out in both clear-water scour and live-bed scour conditions. The bed profiles at different stages of backfill process were measured by a laser profiler. It was found that the upstream part of the trench was backfilled faster than the downstream part. In the early stage of the backfill process, sand in front of the pipeline was washed into the trench very fast. The top part of the sand behind the pipeline was washed away faster while the lower part moved towards the pipeline due to strong vortices. Two-dimensional scour model developed by Zhao and Cheng (2008) was used for simulating the backfill process numerically. This model was validated against van Rijn’s (1986) navigation channel migration experiments and good agreement between experimental data and numerical results was achieved. Numerical simulation of the pipeline trench evolution was carried out under the same conditions used in the laboratory tests. The process of the backfill simulated by the numerical method agreed qualitatively with the test results. The comparison between the numerical and the test results showed that: (1) the simulated backfill rate was greater than the measured one in the upstream side of the pipeline; (2) the sand dune downstream the pipeline was washed away slower than the experimental results, and no backfill was observed. The discrepancy between the experimental and numerical results may be attributed to the fact that the empirical formulae used for predicting the bed load and the reference concentration of suspended load were derived from fully-developed straight channel flow tests, while the velocity varied dramatically along the bed in the cases of this study.

On axial compressive behavior of steel fiber reinforced concrete confined by FRP

2021 ◽  
pp. 136943322098165
Author(s):  
Hossein Saberi ◽  
Farzad Hatami ◽  
Alireza Rahai
Keyword(s):  
Reinforced Concrete ◽  
Experimental Test ◽  
Steel Fiber ◽  
Experimental Tests ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Test Results ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Frp Confinement

In this study, the co-effects of steel fibers and FRP confinement on the concrete behavior under the axial compression load are investigated. Thus, the experimental tests were conducted on 18 steel fiber-reinforced concrete (SFRC) specimens confined by FRP. Moreover, 24 existing experimental test results of FRP-confined specimens tested under axial compression are gathered to compile a reliable database for developing a mathematical model. In the conducted experimental tests, the concrete strength was varied as 26 MPa and 32.5 MPa and the steel fiber content was varied as 0.0%, 1.5%, and 3%. The specimens were confined with one and two layers of glass fiber reinforced polymer (GFRP) sheet. The experimental test results show that simultaneously using the steel fibers and FRP confinement in concrete not only significantly increases the peak strength and ultimate strain of concrete but also solves the issue of sudden failure in the FRP-confined concrete. The simulations confirm that the results of the proposed model are in good agreement with those of experimental tests.

Towards a new design with generic modeling and adaptive control of a transformable quadrotor

2021 ◽  
pp. 1-31
Author(s):  
S.H. Derrouaoui ◽  
Y. Bouzid ◽  
M. Guiatni
Keyword(s):  
Adaptive Control ◽  
Control Strategy ◽  
Experimental Tests ◽  
Generic Model ◽  
System Control ◽  
System A ◽  
Viable Solution ◽  
Generic Modeling ◽  
Adaptive Control Strategy ◽  
The Stability

Abstract Recently, transformable Unmanned Aerial Vehicles (UAVs) have become a subject of great interest in the field of flying systems, due to their maneuverability, agility and morphological capacities. They can be used for specific missions and in more congested spaces. Moreover, this novel class of UAVs is considered as a viable solution for providing flying robots with specific and versatile functionalities. In this paper, we propose (i) a new design of a transformable quadrotor with (ii) generic modeling and (iii) adaptive control strategy. The proposed UAV is able to change its flight configuration by rotating its four arms independently around a central body, thanks to its adaptive geometry. To simplify and lighten the prototype, a simple mechanism with a light mechanical structure is proposed. Since the Center of Gravity (CoG) of the UAV moves according to the desired morphology of the system, a variation of the inertia and the allocation matrix occurs instantly. These dynamics parameters play an important role in the system control and its stability, representing a key difference compared with the classic quadrotor. Thus, a new generic model is developed, taking into account all these variations together with aerodynamic effects. To validate this model and ensure the stability of the designed UAV, an adaptive backstepping control strategy based on the change in the flight configuration is applied. MATLAB simulations are provided to evaluate and illustrate the performance and efficiency of the proposed controller. Finally, some experimental tests are presented.

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