Experimental Investigation on the Effect of Arm Length on Accuracy of Torque Wrench

2016 ◽  
Vol 853 ◽  
pp. 216-220 ◽  
Author(s):  
You Gang Peng ◽  
Yong Wang
Keyword(s):  
Experimental Investigation ◽  
Structural Design ◽  
Bending Moment ◽  
Theoretical Solution ◽  
Calibration Laboratory ◽  
Moment Measurement ◽  
Torque Wrench ◽  
Actual Use ◽  
Good Agreement

Experiments were carried out to investigate the effect of arm length on the accuracy of two typical conventional torque wrenches, namely, setting type torque wrench (STW) and indicating type torque wrench (ITW). The experiment results demonstrate that the measurement values of STW rises rapidly with decreasing arm length while measured torque of ITW shows irrelevant to arm length. Theoretical solution with respect to STW shows quite good agreement with experiment results. Irrelevance of arm length regard to ITW may be attributable to compensation of bending moment measurement due to proper arrangement of circuit and structural design. In order to conduct a proper assessment at a calibration laboratory or ensure its reliability with reference to actual use conditions, a torque wrench should be used by a customer at the loading point as recommended.

scholarly journals Aerodynamic Design and Strength Analysis of the Wing for the Purpose of Assessing the Influence of the Bell-Shaped Lift Distribution

Aerospace ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 13
Author(s):  
Pavel Hospodář ◽  
Armand Drábek ◽  
Aleš Prachař
Keyword(s):  
Structural Design ◽  
Bending Moment ◽  
Strength Analysis ◽  
Flight Performance ◽  
Fuel Saving ◽  
Reduce Fuel Consumption ◽  
Aerodynamic Design ◽  
Structural Part ◽  
Optimization Loop ◽  
Good Agreement

This article deals with aerodynamic and structural calculations of several wing designs to compare the influence of the shape on the lift distribution. Various shapes of wings for the required lift and bending moment were optimized to minimize drag and thereby reduce fuel consumption. One example was a wing with a bell-shaped lift distribution, which was proposed by Ludwig Prandtl and has been forgotten over the years. The first part of the paper focuses on minimization of the wing drag coefficient by a low fidelity method and the results are compared with the CFD calculation with good agreement. In the structural part of the analysis, the inner layout of the studied wings was designed. The structural design, containing elementary wing components and optimization loop, was carried out to minimize weight with respect to panel buckling. From these calculations the weights of wings were obtained and compared. In the last part of this study, an analysis of flight performance of an airplane with presented wings was performed for a selected flight mission. Results indicated that, for the free optimized wing, the fuel saving was about six percent.

Effects of Scattered Bolt Preload on the Sealing Performance of Pipe Flange Connection With Gaskets Under External Bending Moment and Internal Pressure

2012 ◽  
Author(s):  
Toshiyuki Sawa ◽  
Yoshio Takagi ◽  
Koji Sato ◽  
Yuya Omiya ◽  
Hayato Doi
Keyword(s):  
Internal Pressure ◽  
Bending Moment ◽  
Experimental Result ◽  
Chemical Plants ◽  
Stress Distributions ◽  
Bolt Preload ◽  
Sealing Performance ◽  
Torque Wrench ◽  
History Of ◽  
Good Agreement

Bolted pipe flange connections have been widely used in mechanical structures such as oil, chemical plants and so on. Sometimes leakage accidents occur from the connections. In assembling the pipe flange connections, the bolt preloads are scattered and then the connections are subjected to external bending moment due to earthquake as well as internal pressure. In the present paper, the changes in the axial bolt forces are measured in assembling. The bolts are tightened with torque wrench. Using the history of the bolt force changes, the gasket stress distributions on the connection with gaskets are analyzed using FEM. Then the gasket stress distributions on the connections under external bending moment and internal pressure are analyzed. Using the gasket stress distributions, the amount of leakage of the connections is estimated while the basic gasket characteristics have been measured according to JIS B 2251. The amount of leakage of the connection was measured for the various gasket stresses. The estimated results are in a fairly good agreement with the measured results. It is found that the effect of the scatter of bolt preload is substantial on the sealing performance of the connections. Discussion is made on the sealing characteristics of the connections. The change of axial bolt force obtained from experimental result and FEM result are fairly good agreement.

Experimental investigation and modelling of light scattering in a-Si:H solar cells deposited on glass/ZnO:Al substrates

2002 ◽  
Vol 715 ◽  
Author(s):  
J. Krc ◽  
M. Zeman ◽  
O. Kluth ◽  
F. Smole ◽  
M. Topic
Keyword(s):  
Surface Roughness ◽  
Experimental Investigation ◽  
Solar Cells ◽  
Angular Distribution ◽  
Light Scattering ◽  
Optical Model ◽  
Distribution Functions ◽  
Interface Roughness ◽  
Scattering Parameters ◽  
Good Agreement

AbstractThe descriptive scattering parameters, haze and angular distribution functions of textured ZnO:Al transparent conductive oxides with different surface roughness are measured. An approach to determine the scattering parameters of all internal interfaces in p-i-n a-Si:H solar cells deposited on the glass/ZnO:Al substrates is presented. Using the determined scattering parameters as the input parameters of the optical model, a good agreement between the measured and simulated quantum efficiencies of the p-i-n a-Si:H solar cells with different interface roughness is achieved.

On the Effect of Hull Girder Flexibility on the Vertical Wave Bending Moment for Ultra Large Container Vessels

2012 ◽  
Author(s):  
Ingrid Marie Vincent Andersen ◽  
Jørgen Juncher Jensen
Keyword(s):  
Bending Moment ◽  
Main Concern ◽  
Hull Girder ◽  
Numerical Predictions ◽  
Strip Theory ◽  
Reliability Method ◽  
Non Linear ◽  
Large Container ◽  
The Waves ◽  
Good Agreement

Currently, a number of very large container ships are being built and more are on order, and some concerns have been expressed about the importance of the reduced hull girder stiffness to the wave-induced loads. The main concern is related to the fatigue life, but also a possible increase in the global hull girder loads as consequence of the increased hull flexibility must be considered. This is especially so as the rules of the classification societies do not explicitly account for the effect of hull flexibility on the global loads. In the present paper an analysis has been carried out for the 9,400 TEU container ship used as case-ship in the EU project TULCS (Tools for Ultra Large Container Ships). A non-linear time-domain strip theory is used for the hydrodynamic analysis of the vertical bending moment amidships in sagging and hogging conditions for a flexible and a rigid modelling of the ship. The theory takes into account non-linear radiation forces (memory effects) through the use of a set of higher order differential equations. The non-linear hydrostatic restoring forces and non-linear Froude-Krylov forces are determined accurately at the instantaneous position of the ship in the waves. Slamming forces are determined by a standard momentum formulation. The hull flexibility is modelled as a non-prismatic Timoshenko beam. Generally, good agreement with experimental results and more accurate numerical predictions has previously been obtained in a number of studies. The statistical analysis is done using the First Order Reliability Method (FORM) supplemented with Monte Carlo simulations. Furthermore, strip-theory calculations are compared to model tests in regular waves of different wave lengths using a segmented, flexible model of the case-ship and good agreement is obtained for the longest of the waves. For the shorter waves the agreement is less good. The discrepancy in the amplitudes of the bending moment can most probably be explained by an underestimation on the effect of momentum slamming in the strip-theory applied.

scholarly journals Evaluation of the Coordination of Structural Layers in the Design of Asphalt Pavement

2020 ◽  
Vol 10 (9) ◽  
pp. 3178
Author(s):  
Hao Li ◽  
Naren Fang ◽  
Xuancang Wang ◽  
Chuanhai Wu ◽  
Yang Fang
Keyword(s):  
Structural Design ◽  
Asphalt Pavement ◽  
Material Design ◽  
Evaluation Index ◽  
Area Index ◽  
Test Road ◽  
Actual Use ◽  
Pavement Structure ◽  
Low Efficiency ◽  
Structural Layer

The purpose of asphalt pavement structural design is to get a materially-coordinated and structurally-durable product, and a pavement structure with good road performance by combining the structural layer materials reasonably. However, due to lack of a rational evaluation index on the parameter combinations of structural layer materials, the structural layer materials are poor in terms of coordination, have low efficiency, and the actual use period is much lower than the designed working life. Therefore, it is very important to conduct research evaluating the coordination of the structural layer materials. In this study, the sensitivity of mechanical parameters and equivalent envelope area are proposed as new indexes to evaluate the coordination of material design of asphalt pavement structure layers. Software is developed to calculate the equivalent envelope area that can quantitatively evaluate the coordination among different layers and visualize the mechanical transfer behavior of each structural layer. Based on the equivalent envelope area index, this study incorporates two new steps in the design of pavements, namely the structural form comparison and optimization, and proposes a new structural design process. Finally, the rationality and reliability of the equivalent envelope area index are verified by presenting fatigue life calculation and field verification in a test road. The results propose a clear evaluation index of the coordination of material design of each structural layer, which makes the structural design of the asphalt pavement more scientific and reasonable.

An experimental investigation on structural design of shape memory polymers

2019 ◽  
Vol 28 (9) ◽  
pp. 095017 ◽  
Author(s):  
Nima Roudbarian ◽  
Mahdi Baniasadi ◽  
Mehdi Ansari ◽  
Mostafa Baghani
Keyword(s):  
Experimental Investigation ◽  
Shape Memory ◽  
Structural Design ◽  
Shape Memory Polymers

Theoretical and Experimental Investigation on Forming Limit for TNW700 Titanium Alloy

2014 ◽  
Vol 622-623 ◽  
pp. 340-346 ◽  
Author(s):  
Bao Sheng Liu ◽  
Wei Wu ◽  
Xiu Quan Han
Keyword(s):  
Experimental Investigation ◽  
Titanium Alloy ◽  
High Temperature ◽  
Forming Limit ◽  
Minor Strain ◽  
Resistant Material ◽  
Dimple Rupture ◽  
Short Time ◽  
Fractographic Observation ◽  
Good Agreement

Forming limit is identified to evaluate the formability of sheet metal. The in-plane limit strains of sheets are plotted in a diagram with coordinates of major strain vs. minor strain. TNW700 titanium alloy is a high temperature resistant material. The products made of TNW700 can be used in a long serving period at 500°C, short time at 700°C. In this work, the forming limit of TNW700 will be investigated in theoretical and experimental ways. The experiment to test limit strains was carried out at 750°C under different loading paths. Marciniak – Kuczynski (M-K) model was calculated with Swift constitutive equations to predict the curves of limit strains. The effect of the groove angle on forming limit is that, the same angle on both sides of centerline determines the same FLC, and the limit points shift from left side to right side. The experiment shows that, the formability of TNW700 is not excellent, and it is lower than that of TC4 and TA15 at the same condition. The comparison shows that the curve predicted by M-K model is in a good agreement with that at plane strain, however higher than that in both sides. The fractographic observation shows that the fracture mode of TNW700 is dimple rupture.

Stresses in the vicinity of an unreinforced mitre intersection: An experimental and finite element comparison

2007 ◽  
Vol 42 (5) ◽  
pp. 325-335 ◽  
Author(s):  
J Wood
Keyword(s):  
Experimental Investigation ◽  
Finite Element ◽  
Outer Surface ◽  
Thin Shell ◽  
Hot Spot ◽  
Bending Moment ◽  
Inside Surface ◽  
Elastic Stresses ◽  
Finite Element Approximations ◽  
Shell Finite Element

The experimental investigation reported provides elastic stresses in the vicinity of the unreinforced intersection of a single 90° mitred bend, subjected to an in-plane bending moment. The specimen was extensively strain gauged on the outer surface. A small number of rosettes were also laid on the inside surface close to the welded intersection. The procedures used for the successful installation of the inside surface gauges are discussed. In the experiment, consideration was also given to deflections and rotations. Satisfactory comparisons with adaptive- p thin-shell finite element results were obtained in general and differences are explained in terms of the known experimental variables and finite element approximations. The nature of the stresses at such intersections is discussed and various methods of obtaining fatigue ‘hot-spot’ stresses are considered.

A Thin Shell Theoretical Solution for Two Intersecting Cylindrical Shells Due to External Branch Pipe Moments

2004 ◽  
Author(s):  
M. D. Xue ◽  
D. F. Li ◽  
K. C. Hwang
Keyword(s):  
Thin Shell ◽  
Cylindrical Shells ◽  
Branch Pipe ◽  
Three Dimensional ◽  
Homogeneous Solution ◽  
Displacement Function ◽  
Theoretical Solution ◽  
External Branch ◽  
Particular Solution ◽  
Good Agreement

Two intersecting cylindrical shells subjected to internal pressure and external moment are of common occurrence in pressure vessel and piping industry. The highest stress intensity occurring in the vicinity of junction, which is a complex space curve when the diameter ratio d/D increases. As the new process of theoretical solution and design criteria research developed by the authors, the stress analysis based on the theory of thin shell is carried out for cylindrical shells with normally intersecting nozzles subjected to three kinds of external branch pipe moments. The thin shell theoretical solution for the main shell with cutout, on which a moment is applied, is obtained by superposing a particular solution on the homogeneous solution. The double trigonometric series solution of cylindrical shell subjected to arbitrary distributed normal and tangential forces based on Timoshenko equation is used for the particular solution and the Xue et al.’s solution, for the homogeneous solution based on the modified Morley equation instead of the Donnell shallow shell equation. The displacement function solution for the nozzle with a nonplanar end is obtained on the basis of the Goldenveizer equation instead of Timoshenko’s. The presented results are in good agreement with those obtained by experiments and by three-dimensional finite element method. The present analytical results are in good agreement with WRC Bulletin 297 when d/D is small. The theoretical solution can be applied to d/D ≤ 0.8, λ = d/DT ≤ 8 and d/D ≤ t/T ≤ 2 successfully.

Sign in / Sign up

Export Citation Format

Share Document