Penetration depth and tip radius dependence on the correction factor in nanoindentation measurements

2008 ◽  
Vol 23 (3) ◽  
pp. 725-731 ◽  
Author(s):  
J.M. Meza ◽  
F. Abbes ◽  
M. Troyon
Keyword(s):  
Penetration Depth ◽  
Correction Factor ◽  
Contact Stiffness ◽  
Nanoindentation Test ◽  
Simple Analytical Model ◽  
Element Analysis ◽  
Maximum Penetration Depth ◽  
Maximum Penetration ◽  
Tip Radius ◽  
Indenter Geometry

Dimensional analysis is used to show that the maximum penetration depth and the tip radius affect the β correction factor appearing in the Sneddon relationship between unloading contact stiffness, contact area, and elastic modulus. A simple analytical model based on elasticity theory is derived that predicts the variation of β with penetration depth. This model shows that β increases at low penetration depth and decreases with the tip radius. The β(h) curve given by the model is compared with that calculated by finite element analysis for an elastic material and also with that deduced from experimental measurements performed on fused quartz with two Berkovich indenters: a sharp one and a blunted one. It is also demonstrated that the correction factor can be expressed as two multiplicative contributions, a contribution related to the mechanical properties of the material and a contribution related to the indenter geometry. Implications of these findings on nanoindentation test are also discussed.

A response to—“Comment on the evaluation of the constant β relating the contact stiffness to the contact area in nanoindentation for sphero-conical indenters:” Comment to paper “Penetration depth and tip radius dependence on the correction factor in nanoindentation measurements” by J.M. Meza et al. [J. Mater. Res. 23(3), 725 (2008)]

2012 ◽  
Vol 27 (8) ◽  
pp. 1208-1210
Author(s):  
Juan Manuel Meza ◽  
Fazilay Abbes ◽  
Jaime Alexis Garcia Guzman ◽  
Michel Troyon
Keyword(s):  
Penetration Depth ◽  
Correction Factor ◽  
Contact Area ◽  
Contact Stiffness ◽  
Depth Range ◽  
Dimensionless Analysis ◽  
Plastic Materials ◽  
Variation Range ◽  
Elastic Plastic Materials ◽  
Tip Radius

The signification of the correction factor β that we defined for elastic material [J.M. Meza et al. J. Mater. Res.23(3), 725, (2008)] does not correspond to that of factor β in the Sneddon relationship between unloading contact stiffness, elastic modulus, and contact area as remarked by Durst et al. in their Comment (doi:10.1557/jmr.2012.41). To complete the results of Durst et al., the calculation of β is extended to a larger penetration depth range. It is shown that β depends on the depth to tip radius ratio, h/R, and on the Poisson’s ratio according to dimensionless analysis. The variation range of β is about 1.02–1.09 for 0.3 < h/R < 3 for purely elastic materials but can be much larger in case of elastic–plastic materials as shown [F. Abbes et al. J. Micromech. Microeng.20, 65003 (2010)].

Comment to paper “Penetration depth and tip radius dependence on the correction factor in nanoindentation measurements” by J.M. Meza et al. [J. Mater. Res. 23(3), 725 (2008)]

2012 ◽  
Vol 27 (8) ◽  
pp. 1205-1207 ◽  
Author(s):  
Karsten Durst ◽  
Hamad ur Rehman ◽  
Benoit Merle
Keyword(s):  
Finite Element ◽  
Penetration Depth ◽  
Correction Factor ◽  
Elastic Material ◽  
Contact Area ◽  
Contact Stiffness ◽  
Fe Analysis ◽  
Tip Radius ◽  
True Contact Area ◽  
True Contact

[Meza et al. J. Mater. Res.23(3), 725 (2008)] recently claimed that the correction factor beta for the Sneddon equation, used for the evaluation of nanoindentation load-displacement data, is strongly depth- and tip-shape-dependent. Meza et al. used finite element (FE) analysis to simulate the contact between conical or spheroconical indenters, and an elastic material. They calculated the beta factor by comparing the simulated contact stiffness with Sneddon’s prediction for conical indenters. Their analysis is misleading, and it is shown here that by applying the general Sneddon equation, taking into account the true contact area, an almost constant and depth-independent beta factor is obtained for conical, spherical and spheroconical indenter geometries.

Design and Tests of a Multi-pin Flexible Seedling Pick-up Gripper for Automatic Transplanting

2019 ◽  
Vol 35 (6) ◽  
pp. 949-957 ◽  
Author(s):  
Luhua Han ◽  
Francis Kumi ◽  
Hanping Mao ◽  
Jianping Hu
Keyword(s):  
Control System ◽  
Penetration Depth ◽  
Working Pressure ◽  
Pneumatic Control ◽  
Position Detection ◽  
Maximum Penetration Depth ◽  
Timely Response ◽  
Plug Seedling ◽  
Maximum Penetration ◽  
Push Out

HighlightsA multi-pin flexible pick-up gripper with a four-jaw chuck having four pick-up pins has been developed.The gripper can effectively grasp, hold and release plug seedlings with low damages to the plants and the root soil.Based on a typical on-off control and cylinder stroke position detection, the control system for timely response was designed to automate the process of picking up and releasing seedlings.Abstract. A multi-pin flexible seedling pick-up gripper for automatic transplanting was developed and evaluated. The gripper having a four-jaw chuck mainly consists of a parallel-type air gripper with four fingers, four fork frames, four cylinder fingers, and several connecting/supporting parts. The air gripper moves to open and close the cylinder fingers, and the cylinder fingers each having a flexible pin grasp and release the seedling. When the pick-up gripper extracts seedlings from the tray cells, its four cylindrical fingers push out four pick-up pins to penetrate deep into the root soil and then close, making the pick-up pins to firmly hold the root soil for lifting. When the pick-up gripper releases seedlings, its fingers open, making the pick-up pins loosen the root soil and then pull back for discharging. An electrical and pneumatic control system was designed to coordinate the execution of each action. The pick-up gripper attached to a robotic manipulator was tested on a range of plug seedling transplanting parameters and conditions. The results showed that penetration depth, seedling species, and the interaction of working pressure and seedling species significantly influenced the successful automatic transplanting. On the whole, the seedling integrity ratio in automatic transplanting was found to be up to 93.37%. For optimum performance of the device in transplanting seedlings, the pick-up pins of the multi-pin gripper need to grasp the maximum amount of root soil at their maximum penetration depth. Keywords: Gripper, Flexible, Multi-pin, Seedlings, Transplanting.

An Empirical Correlation for Maximum Penetration Depth of a Particle Impacting on a Free Surface at its Critical Velocity Condition

2011 ◽  
Vol 361-363 ◽  
pp. 320-323 ◽  
Author(s):  
Dong Mei Liu ◽  
Geoffrey Michael Evans ◽  
Qing Lin He
Keyword(s):  
Penetration Depth ◽  
Critical Condition ◽  
High Speed ◽  
Least Squares Method ◽  
Density Ratio ◽  
Video Camera ◽  
Empirical Correlation ◽  
Liquid Density ◽  
Maximum Penetration Depth ◽  
Maximum Penetration

Film flotation is a process which consumes much lower energy than mechanical cells. The extended film flotation technique is to separate mineral mixtures by different critical impact velocities. In this study the maximum penetration depth of a particle at its critical condition was investigated experimentally and theoretically. Experiments were performed using spherical glass beads of different diameters and hydrophobicities and different liquids. The penetration depth at critical condition was recorded and measured using high speed video camera. Buckingham’s PI theorem was applied to analyse the dimensionless groups, and then an empirical correlation for penetration depth was obtained by partial least squares method. It was found that the prediction results of the empirical equation were in good agreement with the measurements. Also, the influence factors were analysed. It was noticed that the hydrophobicities of particle and particle-liquid density ratio had most significant effects on the penetration depth.

Modelling of diesel fuel penetration depth in protective sand bed

2020 ◽  
Vol 10 (3) ◽  
pp. 300-304
Author(s):  
Anastasia V. Massold ◽  
◽  
Dzhamil U. Dumbolov ◽  
Alexander V. Dedov ◽  
◽  
...  
Keyword(s):  
Penetration Depth ◽  
Diesel Fuel ◽  
Protective Layer ◽  
Primary Source ◽  
High Rate ◽  
Fuel Distribution ◽  
Maximum Penetration Depth ◽  
Fuel Storage ◽  
Maximum Penetration ◽  
Two Stages

When deploying a temporary fuel storage warehouse, the primary source of soil contamination by oil products is technological losses related to the leakage of isolation valves. To protect the soil from contamination, containers are placed on a layer of sand. The thickness of the sand layer depends on the volume of possible losses. The purpose of the work is to model the depth of diesel fuel penetration into the protective layer of sand bed. The method of performing the experiment imitated a high rate of fuel penetration in the form of droplets onto the protective layer. The article considers the mechanism of fuel penetration into sand and factors, determining the penetration depth. It is established that the mechanism of fuel penetration into the protective layer has two stages, on each of which the penetration depth and rate of fuel distribution are different. The maximum penetration depth is reached on the first stage and depends on the quantity of fuel. The author developed the model, which allows the determination of the thickness of the sand bed protective layer with known granulometric particle composition necessary for the prevention of diesel fuel penetration into soil.

A Corrosion Localization Assessment of the Mild Steel Used for Nuclear Waste Package

1989 ◽  
Vol 176 ◽  
Author(s):  
Masatsune Akashi ◽  
Takanori Fukuda ◽  
Hiroshi Yoneyama
Keyword(s):  
Mild Steel ◽  
Penetration Depth ◽  
Nuclear Waste ◽  
Ultrasonic Inspection ◽  
Gumbel Distribution ◽  
Distribution Model ◽  
Waste Package ◽  
Maximum Penetration Depth ◽  
Maximum Penetration ◽  
High Level

ABSTRACTThis paper describes a study of corrosion behavior of a mild steel as a candidate of the high-level nuclear waste package in the geological disposal situations, conducted to establish a model for estimating the corrosion allowance requirement to achieve the 1,000 year lifetime for the package. In several series of galvanostatic tests, the maximum penetration depth and the depth distribution were measured for each specimen with a sophisticated ultrasonic inspection technique. The Gumbel distribution model was successfully used in analyzing each set of data for the maximum penetration depth. Relations among the average penetration depth, the maximum penetration depth, and the corrosion allowance requirement were discussed.

scholarly journals Estimating Flow Characteristics of Different Weir Types and Optimum Dimensions of Downstream Receiving Pool

2010 ◽  
Vol 58 (4) ◽  
pp. 245-260 ◽  
Author(s):  
M. Emiroglu
Keyword(s):  
Penetration Depth ◽  
Open Channel ◽  
Flow Characteristics ◽  
Channel System ◽  
Maximum Penetration Depth ◽  
Jet Trajectory ◽  
Maximum Penetration ◽  
Labyrinth Weirs ◽  
Bubble Zone ◽  
Free Overfall

Estimating Flow Characteristics of Different Weir Types and Optimum Dimensions of Downstream Receiving PoolThis paper presents the results of a laboratory study on the flow characteristics of sharp-crested weirs, broad-crested weirs, and labyrinth weirs. The variation of the maximum bubble penetration depth for different weir types is investigated depending on overfall jet expansion, discharge, and drop height. Moreover, most efficient depth, length and width of the downstream receiving pool in an open channel system are studied by considering the penetration depth, overfall jet expansion, jet trajectory and the bubble zone. The results show that overfall jet expansion at the labyrinth weirs is significantly wider than the rectangular sharp-crested weirs and the trapezoidal sharp-crested weir. It is demonstrated that the labyrinth weirs have the lowest values of bubble penetration depth among the weirs tested. Furthermore, it is found that the rectangular and the trapezoidal weirs are observed to have the highest bubble penetration depth among all weirs. Consequently, empirical equations are obtained for predicting the maximum penetration depth of bubbles, trajectory of free overfall nappe, jet expansion of free overfall nappe, and the length of the bubble zone.

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