Effect of auxetic honeycomb angular stiffeners in cold-formed perforated and webbed steel upright section under buckling modes

2021 ◽  
pp. 1045389X2110282
Author(s):  
Thasan Selvakumar ◽  
Rajendran Senthil ◽  
Rajan Raj Jawahar ◽  
Soundararajan Lakshmana kumar
Keyword(s):  
Axial Load ◽  
Strain Energy ◽  
Lateral Displacement ◽  
Lateral Load ◽  
Axial Loads ◽  
Buckling Loads ◽  
Buckling Modes ◽  
Steel Columns ◽  
Maximum Resistance ◽  
Lateral Displacements

This work was carried out on the buckling effects of cold-formed perforated steel columns with base auxetic polymer stiffeners. Buckling tests were carried out for three thicknesses of steel profiles (1.5–1.8 mm) with and without base stiffeners. Loading conditions were considered to be with displacement variation of 0.1 mm/s and respective axial loads and lateral displacements were noted. Results obtained states that the lateral displacement was found to be 2.2 for 1.8 mm CFS thickness and 93 kN of axial load with the use of auxetic stiffener with 14.8% of the variation in comparison without stiffener. The strain energy of absorption for auxetic stiffener is found to be high as 0.0523 at a lateral load of 80 kN for 1.8 mm CFS thickness. The maximum resistance to local, distortional, and Euler’s buckling loads was found to be high for 1.8 mm thick CFS with stiffener with 11.1%, 17.39%, and 10% in comparison without stiffener.

Lateral load tests to examine large-strain (seismic) behaviour of piles

1992 ◽  
Vol 29 (2) ◽  
pp. 245-252
Author(s):  
Ernest Naesgaard
Keyword(s):  
Lateral Displacement ◽  
Large Strain ◽  
Field Tests ◽  
Lateral Load ◽  
Soil Liquefaction ◽  
Load Test ◽  
Seismic Behaviour ◽  
Seismic Liquefaction ◽  
Load Tests ◽  
Lateral Displacements

Three different 406 mm diameter piles were tested with lateral, vertical, and moment loadings. The purpose of the full-scale field tests was to assess the ability of the piles to withstand large lateral deformations that may be caused by earthquake-induced soil liquefaction. Two concrete shaft piles were tested to failure with lateral displacements at the pile top of up to 300 and 650 mm and pile curvatures of up to 0.16 and 0.35 rad/m, respectively. The third pile, a concrete-filled steel pipe shaft pile, reached a maximum lateral displacement at the pile top of 550 mm and a curvature of 0.08 rad/m without failure or significant distress. It is concluded that stronger piles that push through the soil may tolerate larger lateral displacements than weaker piles and that reducing the spiral reinforcing pitch from 150to 100 mm on concrete piles greatly increases the pile ductility. Key words : lateral load test, piles, reinforced concrete, concrete-filled pipe, seismic, liquefaction, pile curvature.

Experimental Buckling Investigation of Ring-Stiffened Cylindrical Shells Under Unsymmetrical Axial Loads

1983 ◽  
Vol 105 (4) ◽  
pp. 342-346 ◽  
Author(s):  
W. E. Baker ◽  
J. G. Bennett ◽  
C. D. Babcock
Keyword(s):  
Axial Load ◽  
Numerical Solutions ◽  
Strain Gages ◽  
Axial Loads ◽  
Strain Fields ◽  
Buckling Loads ◽  
Collapse Analysis ◽  
Asme Code ◽  
Stiffened Cylindrical Shells ◽  
Ring Stiffener

Six steel shells having nuclear containmentlike features were fabricated and loaded to failure with an offset axial load. The shells (R/t = 500) buckled plastically. Four of the shells had reinforced circular cutouts. These penetrations were sized to cut no ring-stiffener, a single, two- or three-ring stiffeners. Reinforcing and framing around the penetrations were based upon the area-replacement rule of the applicable portion of the ASME Boiler and Pressure Vessel Code and were of a design to simulate actual practice for nuclear steel containments. Prior to testing, imperfections were measured and strain gages were applied to determine information on load distribution at the ends of the cylinder and strain fields at areas likely to buckle. Buckling loads were determined for an axial load applied with an eccentricity of R/2 where R is the cylinder radius. The results showed that the buckling load and mode for the shell having a penetration that did not cut a ring stiffener were essentially the same as those for the unpenetrated shell. The buckling loads for the penetrated shells in which stiffeners were interrupted were less than that for the unpenetrated shells. Results of all tests are compared to numerical solutions carried out using a nonlinear collapse analysis and to the predictions of ASME Code Case N-284.

scholarly journals Experimental and Numerical Investigations of Composite Concrete–Steel Plate Shear Walls Subjected to Axial Load

2019 ◽  
Vol 5 (11) ◽  
pp. 2402-2422 ◽  
Author(s):  
Jinan Laftah Abbas ◽  
Abbas A. Allawi
Keyword(s):  
Compressive Strength ◽  
Aspect Ratio ◽  
Axial Load ◽  
Steel Plate ◽  
Lateral Displacement ◽  
Load Capacity ◽  
Shear Walls ◽  
Axial Loads ◽  
Axial Load Capacity ◽  
Axial Shortening

This research is presented experimental and numerical investigations of composite concrete-steel plate shear walls under axial loads to predicate the effect of both concrete compressive strength and aspect ratio of the wall on the axial capacity, lateral displacement and axial shortening of the walls. The experimental program includes casting and testing two groups of walls with various aspect ratios. The first group with aspect ratio H/L=1.667 and the second group with aspect ratio H/L=2. Each group consists of three composite concrete -steel plate wall with three targets of cube compressive strength of values 39, 54.75 and 63.3 MPa. The tests result obtained that the increase in concrete compressive strength results in increasing the ultimate axial load capacity of the wall. Thus, the failure load, the corresponding lateral displacement and the axial shortening increased by increasing the compressive strength and the rate of increase  in failure load of the tested walls  was about (34.5% , 23.1%) as compressive strength increased from 39 to 63.3 MPa for case of composite wall  with aspect ratio H/L=1.667 and  H/L=2, respectively. The effect of increasing aspect ratio on the axial load capacity, lateral displacement and axial shortening of the walls was also studied in this study. Compared the main performance characteristic of the testing walls, it can be indicated that the walls with aspect ratio equal to (2) failed under lower axial loads as compared with walls with aspect ratio equal to 1.667 ratios by about (5.8, 12, 15.6 %) at compressive strength (39, 54.75, 63.3 MPa), respectively and experienced large flexural deformations. The mode of failure of all walls was characterized by buckling of steel plates as well as cracking and crushing of concrete in the most compressive zone. Nonlinear three-dimensional finite element analysis is also used to evaluate the performance of the composite wall, by using ABAQUS computer Program (version 6.13). Finite element results were compared with experimental results. The comparison shows good accuracy.

scholarly journals Improved design criterion for frictionally engaged contacts in overrunning clutches

2021 ◽  
Author(s):  
Nadine Nagler ◽  
Armin Lohrengel
Keyword(s):  
Design Process ◽  
Contact Area ◽  
Axial Load ◽  
State Of The Art ◽  
Tangential Force ◽  
Design Criterion ◽  
Hertzian Contact ◽  
Loss Of Function ◽  
Axial Loads ◽  
Improved Design

AbstractOverrunning clutches, also known as freewheel clutches, are frictionally engaged, directional clutches; they transmit torque depending on the Freewheel clutch rings’ rotation directions. The torque causes a tangential force in the Hertzian contact area. The hitherto “state-of-the-art design criterion” bases on this load situation. In practice, axial loads additionally act on the frictionally engaged Hertzian contact area. This additional axial load can cause the loss of the friction connection and so the freewheel clutch slips. This publication presents an improved design criterion for frictionally engaged contacts in freewheel clutches. It allows to consider tangential as well as axial loads during the design process. Additionally, it offers the possibility to estimate the probability of frictional engagement loss and gross slip based on the freewheel clutch’s application scenario. This publication points out how to use the improved design criterion to design freewheel clutches that are more robust against a loss of function.

A Study on the Design Curves for Pultruded Composite Columns

2007 ◽  
Vol 26-28 ◽  
pp. 337-340 ◽  
Author(s):  
Seung Sik Lee ◽  
Soo Ha Chae ◽  
Soon Jong Yoon ◽  
Sun Kyu Cho
Keyword(s):  
Local Mode ◽  
Design Equation ◽  
Global Mode ◽  
Buckling Loads ◽  
Steel Columns ◽  
Short Columns ◽  
Theoretical Approaches ◽  
Interaction Mode ◽  
Column Design ◽  
Thin Walled

The strengths of PFRP thin-walled columns are determined according to the modes of buckling which consist of local mode for short columns, global mode for long columns, and interaction mode between local and global modes for intermediate columns. Unlike the local and global buckling, the buckling strength of interaction mode is not theoretically predictable. Refined theoretical approaches which can account for different elastic properties of each plate component consisting of a PFRP thin-walled member are used. Based on both the analytical buckling loads and the experimentally measured buckling loads from literatures, the accuracies of Ylinen’s equation and modified AISC/LRFD column design equation for isotropic steel columns were compared. From the comparison, it was found that the modified AISC/LRFD column design equation is more suitable for the prediction of the buckling loads of PFRP thin-walled members than Ylinen’s equations.

Behaviour of H-piles supporting an integral abutment bridge

2014 ◽  
Vol 51 (7) ◽  
pp. 713-734 ◽  
Author(s):  
Shelley A. Huntley ◽  
Arun J. Valsangkar
Keyword(s):  
Axial Load ◽  
Integral Abutment ◽  
Integral Abutment Bridges ◽  
Expansion Joints ◽  
Thermal Bridge ◽  
Double Curvature ◽  
Abutment Bridges ◽  
Integral Abutments ◽  
Integral Abutment Bridge ◽  
Lateral Displacements

Integral abutment bridges accommodate thermal superstructure movements through flexible foundations rather than expansion joints. While these structures are a common alternative to conventional design, the literature on measured field stresses in piles supporting integral abutments appears to be quite limited. Therefore, field data from strain gauges installed on the abutment foundation piles of a 76 m long; two-span integral abutment bridge are the focus of this paper. Axial load, weak- and strong-axis bending moments of the foundation piles, as well as abutment movement and backfill response, are presented and discussed. Results indicate that the abutment foundation piles are bending in double curvature about the weak axis, as a result of thermal bridge movements, and bending also about the strong axis due to tilting of the abutments. A simple subgrade modulus approach is used to show its applicability in predicting behaviour under lateral loading. In the past, much emphasis has been placed on the lateral displacements of piles and less on variations of axial load. In this paper, a new hypothesis, which offers insight into the mechanisms behind the observed thermal variations in axial load, is proposed and assessed. The data from the field monitoring are also compared with the limited data reported in the literature.

scholarly journals The design of an “H” joystick for closed reduction and its application in segmental and comminuted femoral shaft fractures: an innovative technique

2020 ◽  
Author(s):  
Zhaofeng Jia ◽  
Shijin Wang ◽  
Tinghui Xiao ◽  
Wei Jiang ◽  
Tianjian Zhou ◽  
...  
Keyword(s):  
Intramedullary Nailing ◽  
Closed Reduction ◽  
Lateral Displacement ◽  
Femoral Fractures ◽  
Femoral Shaft ◽  
Limb Length Discrepancy ◽  
Bony Union ◽  
Femoral Shaft Fractures ◽  
Shaft Fractures ◽  
Lateral Displacements

Abstract Background: Closed reduction and locked intramedullary nailing has become a common surgical method in the treatment of femoral shaft fractures. Overlap and rotation displacements can usually be corrected through the use of an orthopaedic traction table. However, lateral displacement and angulation persist. Methods: In this paper, we describe a joystick that can be used in the closed reduction of a fracture. It can correct lateral displacement and angulation and has the advantage of multi-direction reduction. The device described in this paper includes two parallel horizontal joysticks, one vertical main joystick and four assistant rods. Moreover, there are many specific spacing holes in the two parallel horizontal joysticks and a groove structure in the vertical main joystick. When the main “H” joystick is pressed, it can adjust lateral displacements and angulation because of the lever principle. The distance between parallel horizontal joysticks and assistant rods can be adjusted to the fracture position and body mass index of different patients. Results: The study participants consisted of 11 males and 5 females with a mean age of 31.0 years. All participants had good closed reduction and achieved bony union without any complications such as infection, nerve injury, nonunion, malunion and limb length discrepancy. By using an “H” joystick, closed femoral shaft fracture reduction and locked intramedullary nailing becomes simpler and faster. Conclusion: Based on the use of this instrument, we can easily and conveniently obtain the correct reduction situation, which leads to better surgical results. This device can be applied in the reduction of clinical femoral fractures and gradually extended to the reduction of other fractures.

scholarly journals Comparative Evaluation of Concentric Bracing Systems for Lateral Loads on Medium Rise Steel Building Structures

2020 ◽  
pp. 124-130
Author(s):  
Sisaynew Tesfaw Admassu
Keyword(s):  
Lateral Displacement ◽  
Level Structure ◽  
Lateral Load ◽  
Frame Structure ◽  
Lateral Stiffness ◽  
Building Structures ◽  
Steel Buildings ◽  
Lateral Strength ◽  
Strength And Stiffness ◽  
Bracing System

To resistance, the lateral load from wind or an earthquake is that the reason for the evolution of varied structural systems. Because, when a medium or any multi-level structure is exposed to horizontal or torsional deflections under the action of seismic burdens. Lateral stiffness is a major consideration in the design of the buildings. In addition to this, many existing steel buildings and reinforced concrete buildings for which the weak lateral stiffness is the main problem; should be retrofitted to conquer the insufficiencies to resist the lateral loading. Lateral load resisting systems are structural elements providing basic lateral strength and stiffness, without which the structure would be laterally unstable. The unstable nature of the structure is solved by the fitting arrangement of bracings systems. A bracing system is that forms an integral part of the frame. Thus, such a structure has to be analyzed before arriving at the best type or effective arrangement of bracing. Bracing is a highly effective strategy of resisting lateral forces in a frame structure. In this document, a ten-story building with incorporated bracing systems is analysed using ETABS 2016 analysis software as per Eurocode and Ethiopian Building Code Standards (EBCS). Then, the lateral displacement is evaluated under each of the bracing types.

scholarly journals The seismic performance of steel encased reinforced concrete bridge piles

1983 ◽  
Vol 16 (2) ◽  
pp. 123-140
Author(s):  
R. J. T. Park ◽  
M. J. N. Priestley ◽  
W. R. Walpole
Keyword(s):  
Reinforced Concrete ◽  
Seismic Performance ◽  
Theoretical Investigation ◽  
Axial Load ◽  
Lateral Displacement ◽  
Load Level ◽  
Concrete Bridge ◽  
Reinforced Concrete Bridge ◽  
Outside Diameter ◽  
Good Agreement

An experimental and theoretical investigation into the seismic performance of steel encased reinforced concrete bridge piles is described. Six test units were designed, constructed and tested
under cyclic lateral displacement-controlled loading. The units had
an outside diameter of 360 mm and a steel casing thickness of 5 mm. Variables included the axial load level, inclusion or exclusion of internal reinforcing cages, and the influence of the casing continuity at he critical flexural sections. Sound seismic performance was observed in all of the models and good agreement between predicted and observed ultimate behaviour was obtained.

The Role of Adhesive in the Load Response of Adhesively Bonded Aluminum Hat Sections Under Axial Compression

2001 ◽  
Author(s):  
Jianping Lu ◽  
Golam M. Newaz ◽  
Ronald F. Gibson
Keyword(s):  
Compressive Strength ◽  
Plastic Collapse ◽  
Adhesively Bonded ◽  
Buckling Mode ◽  
Buckling Loads ◽  
Buckling Modes ◽  
Load Response ◽  
Peak Loads ◽  
Post Buckling

Abstract Aluminum hat section, either adhesively bonded or unbonded, experiences buckling, post buckling and plastic collapse when axially compressed. However, there exist obvious differences in the load response between the bonded and unbonded hat sections. Finite element eigenvalue buckling analysis is carried out to predict the buckling load and mode. Experiments show that when adhesively bonded hat sections begin to buckle there is a transformation from the first buckling mode to the higher ones, while the unbonded hat sections develop the post buckling based on the lowest buckling mode. The different buckling modes result in not only different buckling loads but different peak loads of the hat sections as well. Finally, the ultimate compressive strength formulae are proposed for the hat sections.

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