Slip modulus in bolted timber joints

1992 ◽  
Vol 19 (6) ◽  
pp. 960-964 ◽  
Author(s):  
D. B. Van Dyer
Keyword(s):  
Test Results ◽  
Lateral Loads ◽  
Initial Load ◽  
Theoretical Predictions ◽  
Mechanically Fastened ◽  
Timber Joints ◽  
Interlayer Slip ◽  
Laterally Loaded ◽  
Wood Columns ◽  
Good Agreement

This paper is concerned with the initial load–slip behaviour of laterally loaded bolted timber joints and deals specifically with verifying a theory for determining the values of slip modulus in mechanically fastened timber joints. Such a theory is essential in dealing with the phenomenon of interlayer slip, which occurs in built-up timber columns with nonrigid joints. The concept of a beam on an elastic foundation is used to evaluate the slip modulus. The theoretical predictions are compared with the test results of 75 timber joints. Good agreement is observed between the experiment and the theory. Key words: timber joints, bolts, nails, wood, interlayer slip, slip modulus, built-up wood columns, shear, lateral loads.

Strength and efficiency of braced timber columns

1992 ◽  
Vol 19 (1) ◽  
pp. 186-189
Author(s):  
D. B. Van Dyer
Keyword(s):  
Structural Engineering ◽  
Theoretical Development ◽  
Timber Construction ◽  
Theoretical Predictions ◽  
Rational Procedure ◽  
Layered Solid ◽  
Interlayer Slip ◽  
Wood Columns ◽  
Construction Wood ◽  
Good Agreement

A rational procedure for determining the strength of braced timber columns is presented. The theoretical development takes into account the effects of interlayer slip, a phenomenon characteristic of systems with nonrigid connections. Forty-five braced wood columns were fabricated and tested. Very good agreement was observed between experimental results and theoretical predictions. As a measure of efficiency, the braced column results are compared with equivalent layered and equivalent solid systems. Key words: buckling, columns, nails, braced columns, structural engineering, nonrigid connections, timber construction, wood columns, layered, solid.

scholarly journals An Investigation into the Effect of Cracking on the Response of Drilled and Postgrouted Concrete Pipe Pile under Lateral Loading

2020 ◽  
Vol 2020 ◽  
pp. 1-12 ◽  
Author(s):  
Zhijun Yang ◽  
Qing Fang ◽  
Bu Lv ◽  
Can Mei ◽  
Xudong Fu
Keyword(s):  
Flexural Rigidity ◽  
Bending Moment ◽  
Test Results ◽  
Lateral Loads ◽  
Analysis Method ◽  
Pile Head ◽  
Laterally Loaded Piles ◽  
Pipe Pile ◽  
Concrete Pipe ◽  
Laterally Loaded

The cracks are likely to initiate on a lateral loaded pile and would cause greater deflection at the pile head. However, there is a lack of thorough investigation into the effect of cracking on the response of the lateral loaded pile. In this article, a full-scale field test was carried out to investigate the behavior of Drilled and Postgrouted Concrete Pipe Pile under lateral loads. A novel analysis method for the lateral loaded pile, which can take the cracking effects into consideration, was proposed, and the validity was verified by the test results. With the proposed method, the cracking effects on flexural rigidity, displacement, rotation, and bending moment of the pile were studied. In brief, cracking effect would dramatically reduce the flexural rigidity of the pile, remarkable increase the displacement and rotation of the pile top, and slightly decrease bending moment of the pile. Unambiguously, the results show that the proposed method can excellently predict the response of laterally loaded piles under cracking effects.

The RMS Characteristics of Acceleration and Force Signals Depending on Tool Wear in Stable Cutting

1999 ◽  
Author(s):  
Richard Y. Chiou ◽  
Y. K. Kwon ◽  
Steven Y. Liang
Keyword(s):  
Tool Wear ◽  
Random Vibration ◽  
Cutting Tool ◽  
Flank Wear ◽  
Mean Square ◽  
Test Results ◽  
Tool Holder ◽  
Theoretical Predictions ◽  
Acceleration Signals ◽  
Good Agreement

Abstract An analysis of the RMS (Root Mean Square) characteristics of fluctuating force and acceleration signals for a cutting tool engaged in a turning operation in the presence of wear flat on the tool flank is presented in this research. The RMS of acceleration and force signals obtained from experiments in stable cutting is compared with theoretical machining models due to the tool wear effect. The RMS is a measure of the energy, at the tool tip-workpiece interface along the flank, to the random vibration of the cantilever portion of the tool holder. Increasing flank wear results in an increasing stability and decreasing RMS in the thrust direction, dependent upon flank wear-land width. The RMS force and acceleration signals in machining is calculated by frequency band RMS method at the first natural frequency of the cantilever portion of the tool holder in the frequency domain. By reference to experimental evidence, the theoretical predictions show generally good agreement with test results.

The Bearing Capacity of Rigid Piles Under Inclined Loads in Sand. II: Batter Piles

1973 ◽  
Vol 10 (1) ◽  
pp. 71-85 ◽  
Author(s):  
G. G. Meyerhof ◽  
Gopal Ranjan
Keyword(s):  
Bearing Capacity ◽  
Previous Investigation ◽  
Test Results ◽  
Inclined Load ◽  
Inclined Loads ◽  
Loading Tests ◽  
Batter Piles ◽  
Laterally Loaded ◽  
Ultimate Resistance ◽  
Good Agreement

Following the previous investigation reported in the first part on vertical piles, this second part of the paper presents an analysis of the results of loading tests on rigid batter piles under inclined load in sand. The bearing capacity of axially loaded batter piles is discussed by comparing experimental results and theoretical estimates. The theory for ultimate resistance of rigid vertical piles under horizontal loads is extended to that of laterally loaded batter piles. Model test results are compared with those of theoretical estimates and good agreement is found. Methods of analysis of vertical piles under inclined loads are extended to those of rigid batter piles under inclined loads in sand and the analysis is compared with some test results.

Strength of spaced timber columns

1985 ◽  
Vol 12 (1) ◽  
pp. 36-42 ◽  
Author(s):  
D. B. Van Dyer ◽  
S. K. Malhotra
Keyword(s):  
Structural Engineering ◽  
Theoretical Development ◽  
Layered Systems ◽  
Split Ring ◽  
Timber Construction ◽  
Theoretical Predictions ◽  
Rational Procedure ◽  
Interlayer Slip ◽  
Practice Efficiency ◽  
Good Agreement

A rational procedure for determining the strength of spaced timber columns is presented. The effect of interlayer slip, characteristic of layered systems with nonrigid connections, is considered in the theoretical development. A good agreement is observed between the theoretical predictions and experimental results of some 110 spaced columns. The effect of number of spacer blocks on column strength is investigated, and efficiency of various types of spaced columns is compared, first with respect to each other and then with respect to equivalent solid and layered systems. Finally, the theory is compared with design specifications given by CSA Standard CAN3-086-M80, "Code for engineering design in wood." Key words: bolts, buckling, columns (supports), design practice, efficiency, nails, nonrigid connection, spaced columns, split ring connectors, strength, structural engineering, tests, theory, timber construction.

Effect of Relative Density on P-Y Backbone Curves for Cyclic Lateral Load on Pile Foundations in Sandy Soil

2014 ◽  
Author(s):  
Sung-Ha Baek ◽  
Joon-Young Kim ◽  
Seung-Hwan Lee ◽  
Choong-Ki Chung
Keyword(s):  
Relative Density ◽  
Sandy Soil ◽  
Sandy Soils ◽  
Pile Foundations ◽  
Test Results ◽  
Lateral Loads ◽  
Laterally Loaded Piles ◽  
Cyclic Lateral Load ◽  
Subgrade Modulus ◽  
Laterally Loaded

Pile foundations installed to support offshore structures are primarily subjected to cyclic lateral loads due to wind, and waves. The p-y curve method, which represents a nonlinear relation between soil-pile reaction and lateral pile deflection, has been used to design cyclic laterally loaded piles. Recommended by the American Petroleum Institute (API) [10] and generally adopted to evaluate the behavior of static and cyclic laterally loaded piles installed in sandy soils, the API p-y curve contains a reduction factor for the initial horizontal subgrade modulus in order to take cyclic effects into consideration. When pile foundations are subjected to cyclic lateral loads, however, the initial horizontal subgrade modulus can both decrease and increase according to the relative density of the soil. In this paper, a series of cyclic lateral load model tests were performed on a preinstalled aluminum flexible pile to examine its cyclic lateral response under different relative density conditions. Model piles were embedded in sandy soils with relative densities of 40%, 70%, and 90% and were subjected to static as well as cyclic lateral loads. From the test results, cyclic p-y backbone curves were derived and compared with static p-y curves in identical soil conditions. Test results showed that the initial horizontal subgrade modulus increased for the model pile installed in sandy soil of 40% relative density, while decreased in relative densities of 70% and 90%. In addition, the infinite depth, above which cyclic lateral loads were supported, was evaluated and the test results were compared with the API p-y curve.

IMPACT ANALYSIS AND TEST FOR THE SPACER GRID ASSEMBLY OF A NUCLEAR FUEL ASSEMBLY

2008 ◽  
Vol 22 (09n11) ◽  
pp. 1228-1234 ◽  
Author(s):  
KEE-NAM SONG ◽  
SANG-HOON LEE ◽  
SOO-BUM LEE
Keyword(s):  
Fuel Assembly ◽  
Nuclear Fuel ◽  
Impact Analysis ◽  
Test Results ◽  
Lateral Loads ◽  
Spacer Grid ◽  
Element Analysis ◽  
Nuclear Fuel Assembly ◽  
Crush Strength ◽  
Good Agreement

A spacer grid assembly is one of the main structural components of the nuclear fuel assembly for a Pressurized light Water Reactor (PWR). The spacer grid assembly supports and aligns the fuel rods, guides the fuel assemblies past each other during a handling and, if needed, sustains lateral seismic loads. The ability of a spacer grid assembly to resist these lateral loads is usually characterized in terms of its dynamic and static crush strengths, which are acquired from tests. In this study, a finite element analysis on the dynamic crush strength of spacer grid assembly specimens is carried out. Comparisons show that the analysis results are in good agreement with the test results to within about a 30 % difference range. Therefore, we could predict the crush strength of a spacer grid assembly in advance, before performing a dynamic crush test. And also a parametric study on the crush strength of a spacer grid assembly is carried out by adjusting the weld penetration depth for a sub-sized spacer grid, which also shows a good agreement between the test and analysis results.

An R-Curve Approach for Fracture of Ultra High Performance Cementitious Composites

2007 ◽  
Vol 348-349 ◽  
pp. 825-828
Author(s):  
Xiang Guo Wu ◽  
Sang Mook Han ◽  
Sung Wook Kim ◽  
Su Tae Kang
Keyword(s):  
Stress Intensity Factor ◽  
High Performance ◽  
Steel Fiber ◽  
Unit Area ◽  
Cementitious Composites ◽  
Test Results ◽  
Linear Distribution ◽  
Three Point Bending ◽  
Theoretical Predictions ◽  
Good Agreement

An R-curve formula for ultra high performance cementitious composites is derived in this paper. The fracture mechanics based on R-curve is used to predict the load-deflection relation of ultra high performance cementitious composites. The reductions of stress intensity factor and CTOD by steel fiber reinforcement are assumed as conforming linear distribution along crack propagation. The effective numbers of steel fiber on unit area based uniform distribution is used here. Results of the theoretical predictions show a good agreement with test results of three point bending beam of UHPCC. The modified R-curve formula for UHPCC can be a reference for future study of fracture performances of UHPCC.

Impact Analysis and Test of the Spacer Grid Assembly for PWRs

2006 ◽  
Vol 326-328 ◽  
pp. 1555-1558
Author(s):  
Kee Nam Song ◽  
Kyung Ho Yoon ◽  
Jae Jun Lee ◽  
Kyung Jin Park
Keyword(s):  
Impact Analysis ◽  
Dynamic Buckling ◽  
Test Results ◽  
Lateral Loads ◽  
Spacer Grid ◽  
Nuclear Fuel Assembly ◽  
Fuel Assemblies ◽  
Buckling Test ◽  
Crush Strength ◽  
Good Agreement

The spacer grid assembly, which is an interconnected array of slotted grid straps and welded at the intersections to form an egg crate structure, is one of the main structural components of the nuclear fuel assembly of a Pressurized light Water Reactor (PWR). The spacer grid assembly supports and aligns the fuel rods, guides the fuel assemblies past each other during handling and, if needed, sustains lateral seismic loads. The ability of the spacer grid assembly to resist the lateral loads is usually characterized in terms of its dynamic and static crush strengths, which are acquired from tests. In this study, dynamic buckling tests and finite element analyses on spacer grid assembly specimens are carried out. Comparisons show that the analysis results are in good agreement with the test results to within an 8 % difference range. Therefore, we could predict the crush strength of a spacer grid assembly in advance before performing the dynamic buckling test.

A theoretical model for the tread slip and the effective rolling radius of the tyres in free rolling

2017 ◽  
Vol 231 (11) ◽  
pp. 1461-1470 ◽  
Author(s):  
Yintao Wei ◽  
Christian Oertel ◽  
Xuebing Li ◽  
Liangyao Yu
Keyword(s):  
Lateral Displacement ◽  
Rotational Velocity ◽  
Rolling Friction ◽  
Test Results ◽  
Inflation Pressure ◽  
Displacement Gradient ◽  
Theoretical Predictions ◽  
Circumferential Displacement ◽  
Increasing Load ◽  
Good Agreement

A rigid–elastic coupling theory for the rolling kinematics of tyres, by which the tread slip, the effective rolling radius and the ply steering of the tyres can be analysed, was formulated. The theory demonstrates that, during free-rolling motion, the coupling between the rotational velocity Ω along the wheel axis and the circumferential displacement gradient generates the longitudinal tread slip, and the coupling between the rotational velocity Ω along the wheel axis and the lateral displacement gradient generates the lateral tread slip and the ply steering. Revisiting the tread slip phenomenon using the newly proposed method numerically proves the kinematic mechanism of the rolling friction. It can be found that the effective rolling radius Re increases with increasing inflation pressure and decreases with increasing load; the sensitivity of Re to the inflation pressure is greater than the sensitivity of Re to the load. The good agreement between the theoretical predictions and the test results for the effective rolling radius of the radial tyres of a car is found. The coupling of the displacement gradient and the rigid rolling kinematics causes non-symmetry of the lateral tread slip which, in turn, leads to the ply steering and the residual aligning moment; these depend on the belt and tread design. The proposed theory and approach provide a quick and powerful tool for analysing the tread slip, the effective rolling radius and the ply steering of the tyres under free rolling.

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