Finite Element Modeling and Simulations to Investigate the Relationship between the Cone Index Profile and Draft Requirements of a Compaction Profile Sensor with Depth

2018 ◽  
Vol 61 (1) ◽  
pp. 37-43 ◽  
Author(s):  
Qingsong Zhang ◽  
Shrini K. Upadhyaya ◽  
Qingxi Liao ◽  
Pedro Andrade-Sanchez
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Yield Criterion ◽  
Empirical Relationship ◽  
Cutting Edge ◽  
Soil Types ◽  
Element Modeling ◽  
Wide Range ◽  
The Relationship ◽  
Cone Index

Abstract. Previous research conducted using a compaction profile sensor and a standard cone penetrometer over a wide range of soil types and conditions found that the unit pressure acting on the cutting edge, defined as the cone index equivalent (CIE), at a specific depth (d) was related to the cone index (CI) value at that depth, the depth of the cutting edge (d), and the interaction between CI and the depth of the cutting edge (i.e., CI × d) with a very high coefficient of multiple determination irrespective of the soil type and conditions. The objective of this study was to provide an analytical basis for the relationship between CIE and CI. A two-dimensional axisymmetric model for soil-cone interaction and a three-dimensional model for soil-tine interaction were developed using a finite element method (FEM). A non-linear elasto-plastic constitutive behavior along with the Drucker-Prager yield criterion were used to represent the soil cutting process. Simulations studies were conducted in 25 distinct soil types and conditions, and the results indicated a similar relationship between CIE and CI, as observed in the previous research. These results support the existence of a strong theoretical basis for the empirical relationship observed in the previous research. Keywords: Cone index, Compaction profile sensor, Finite element modeling, Soil penetration resistance.

scholarly journals Modeling indentation in linear viscoelastic solids

2004 ◽  
Vol 841 ◽  
Author(s):  
Yang-Tse Cheng ◽  
Che-Min Cheng
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Viscoelastic Properties ◽  
Viscoelastic Solids ◽  
Element Modeling ◽  
Elastic Plastic ◽  
Contact Depth ◽  
Linear Viscoelastic ◽  
The Relationship ◽  
Conical Indentation

ABSTRACTUsing analytical and finite element modeling, we study conical indentation in linear viscoelastic solids and examine the relationship between initial unloading slope, contact depth, and viscoelastic properties. We will then discuss whether the Oliver-Pharr method for determining contact depth, originally proposed for indentation in elastic and elastic-plastic solids, is applicable to indentation in viscoelastic solids.

Modeling and Experimental Research Regarding the Temperature Distribution along Curved Cutting Edges

2014 ◽  
Vol 1036 ◽  
pp. 259-264
Author(s):  
Nicușor Baroiu ◽  
Doina Boazu ◽  
Silviu Berbinschi ◽  
Virgil Teodor
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Cutting Tools ◽  
Chip Thickness ◽  
Cutting Edge ◽  
Actual Process ◽  
Element Modeling ◽  
Temperature State ◽  
Machining Speed ◽  
Twist Drills

The curved cutting edge determines a variable chip thickness that leads to various may energetically load along the cutting edge. For twist drill with curved cutting edges, the machining speed variation along the major cutting edge is significant. The points belong to the drills periphery work with an increased machining speed. The thick of the detached chip by these cutting zones downwards to the periphery, versus the thick corresponding to the zones at the drills axis, may leads, in some conditions, to the evenness of the energetically load along the cutting edge, with direct influence regarding the cutting tools wearing mechanism. In this paper are presented modeling with finite elements developed in the Ansys Workbench environment, regarding the energetically load and the temperature state along the cutting edge with variable working angle, characteristic for twist drills with curved cutting edges. The modeling was made comparative with the drill with straight lined cutting edges, for the same working conditions. In the same time, presents an experimental record of an actual process. It was recorded the temperature along the cutting edge with a variable working angle in a turning process with transversal feed. There are presented results of the finite element modeling and of the experiment that simulated the cutting process at drilling. The experimental results of the finite element modeling confirm the trend for temperature evenness along the cutting edge with variable working angle regarding the drills with straight-line cutting edge.

Finite Element Modeling of Nanoindentation Measurements of Crystalline and Amorphous Si

2000 ◽  
Vol 649 ◽  
Author(s):  
J. A. Knapp ◽  
D. M. Follstaedt ◽  
S. M. Myers ◽  
G. A. Petersen
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Finite Element Modeling ◽  
Yield Criterion ◽  
Phase Changes ◽  
Element Modeling ◽  
Atomic Force ◽  
Nanoindentation Testing ◽  
Amorphous Si ◽  
Indentation Measurement

ABSTRACTNanoindentation testing of amorphous Si layers, formed by self-ion implantation, has been performed, and their mechanical properties compared to crystalline Si. The data was analyzed using finite element modeling of the indentation measurement, allowing the properties of the thin amorphous layers to be separated from those of the underlying material. By modeling the materials as isotropic, elastic-plastic solids with the Mises yield criterion, the amorphous Si is shown to have a hardness about 15% lower than crystalline Si and an elastic modulus about 10% lower. Electron and atomic force microscopies of the indents indicate that the amorphous Si does not undergo phase changes during indentation, and that it may be somewhat more ductile than crystalline Si.

Influence of Process Parameters on Electric Upsetting Process by Using Finite Element Modeling

2017 ◽  
Vol 728 ◽  
pp. 42-47 ◽  
Author(s):  
Pattarapong Nuasri ◽  
Yingyot Aue-u-Lan
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Material Flow ◽  
Electric Heating ◽  
Heating System ◽  
Forming Process ◽  
Influence Of Process Parameters ◽  
Element Modeling ◽  
Electric Upsetting ◽  
The Relationship

Electric Upsetting Process (EUP) is a process combining the forming process with the electric heating system. It is commonly used to manufacture a preform of a bar with high upsetting ratio, such as an axial shaft. The reliable forming process requires the understanding the effect of process and electrical parameters. Currently, the designer develops this process by trail-and-error. To successfully develop this process, the relationship between the electric heating and the forming parameters needs to be clearly understood. In this study, three parameters are investigated; namely anvil speed, upsetting load and heating voltage. Finite Element Modeling (FEM) is used as a tool for evaluating these parameters. The FEM results indicate that those parameters play significant roles on the material flow as well as the heating characteristics (i.e. temperature distributions and heat flow).

Closed-Loop High-Fidelity Simulation Integrating Finite Element Modeling With Feedback Controls in Additive Manufacturing

2020 ◽  
Vol 143 (2) ◽  
Author(s):  
Dan Wang ◽  
Xu Chen
Keyword(s):  
Finite Element ◽  
Additive Manufacturing ◽  
Finite Element Modeling ◽  
Closed Loop ◽  
Agile Manufacturing ◽  
High Fidelity ◽  
Feedback Controls ◽  
Element Modeling ◽  
Melt Pool ◽  
Wide Range

Abstract A high-precision additive manufacturing (AM) process, powder bed fusion (PBF) has enabled unmatched agile manufacturing of a wide range of products from engine components to medical implants. While finite element modeling and closed-loop control have been identified key for predicting and engineering part qualities in PBF, existing results in each realm are developed in opposite computational architectures wildly different in time scale. This paper builds a first-instance closed-loop simulation framework by integrating high-fidelity finite element modeling with feedback controls originally developed for general mechatronics systems. By utilizing the output signals (e.g., melt pool width) retrieved from the finite element model (FEM) to update directly the control signals (e.g., laser power) sent to the model, the proposed closed-loop framework enables testing the limits of advanced controls in PBF and surveying the parameter space fully to generate more predictable part qualities. Along the course of formulating the framework, we verify the FEM by comparing its results with experimental and analytical solutions and then use the FEM to understand the melt-pool evolution induced by the in- and cross-layer thermomechanical interactions. From there, we build a repetitive control (RC) algorithm to attenuate variations of the melt pool width.

Finite Element Modeling of a Tennis Racket with Variable String Patterns and Tensions

1990 ◽  
Vol 6 (1) ◽  
pp. 78-91 ◽  
Author(s):  
Mary Ann Bitz Widing ◽  
Manssour H. Moeinzadeh
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Material Properties ◽  
String Tension ◽  
Tennis Racket ◽  
Element Modeling ◽  
Reaction Forces ◽  
String Pattern ◽  
Curved Elements ◽  
The Relationship

Finite element techniques were applied in a model of a tennis racket. Linear curved elements were used on the frame of the racket. Nonlinear cable elements were used on the strings. The model allows changing material properties and frame geometry, as do traditional models. Unlike traditional models, however, this model has the flexibility to change the string pattern and string tensions, as the strings are modeled discretely. Sample runs revealed information on the relationship between racket parameters and racket behavior such as deformations, stresses, and reaction forces. The results of the model showed that increasing string tension decreases racket deformation as string tension stiffens the racket. Increased string tension also decreases maximum hand reaction forces but increases stresses.

Improved Efficiency of Microdiffuser Through Geometry Tuning for Valveless Micropumps

2015 ◽  
Vol 138 (3) ◽  
Author(s):  
Arvind Chandrasekaran ◽  
Muthukumaran Packirisamy
Keyword(s):  
Finite Element ◽  
Pressure Drop ◽  
Finite Element Modeling ◽  
Flow Conditions ◽  
Element Modeling ◽  
Valveless Micropump ◽  
Wide Range

Flow rectification in a mechanical valveless micropump that has applications in biological and microrocket propulsion is brought about by pressure drop created across the nozzle/diffuser pair in conjunction with the actuation stroke of the micropump. It has been reported that geometric tuning of the diffuser helps in improving the overall diffuser efficiency. The aim of the present work is to apply the geometry tuning principle over a wide range of flow conditions and to study the usability of this technique for optimized micropump design. Finite element modeling (FEM) of the diffuser behavior with geometry tuning has been carried out for different diffuser configurations and flow conditions, and the results have been validated through selective experimentation.

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