Measurement of the viscoelastic properties of materials with a very large loss factor by a two-parameter method

1997 ◽  
Vol 40 (3) ◽  
pp. 251-254
Author(s):  
V. M. Kulik ◽  
S. L. Morozova
Keyword(s):  
Viscoelastic Properties ◽  
Loss Factor ◽  
Parameter Method ◽  
Large Loss ◽  
Properties Of Materials ◽  
Two Parameter

Stability of Flat Plate Boundary Layer Over Compliant Coating with Increased Rigidity

2011 ◽  
Vol 6 (4) ◽  
pp. 25-41
Author(s):  
Andrey Boiko ◽  
Viktor Kulik ◽  
V. Filimonov
Keyword(s):  
Boundary Layer ◽  
Reynolds Number ◽  
Viscoelastic Properties ◽  
Loss Factor ◽  
Plate Boundary ◽  
Single Layer ◽  
Interface Conditions ◽  
Compliant Coating ◽  
Blasius Boundary Layer ◽  
Flat Plate Boundary Layer

In the paper the results of hydrodynamic stability computations for Blasius boundary layer over single-layer compliant coatings in the framework of complete (in respect to interface conditions) linear quasi-parallel approach are presented. Data on viscoelastic properties (elastic modulus and loss factor) of the coatings as functions of frequency obtained in a series of special experiments were used. A range of the coating parameters, which provide a compromise between their rigidity and intensity of interaction with the flow, was determined. Based on en -method, estimations of the transition Reynolds number were done

Analytic Approximations to Nonlinear Boundary Value Problems Modeling Beam-Type Nano-Electromechanical Systems

2017 ◽  
Vol 72 (3) ◽  
pp. 201-206
Author(s):  
Li Zou ◽  
Songxin Liang ◽  
Yawei Li ◽  
David J. Jeffrey
Keyword(s):  
Boundary Value Problems ◽  
Nonlinear Boundary ◽  
Boundary Value ◽  
Parameter Method ◽  
Nonlinear Boundary Value Problems ◽  
Electromechanical Systems ◽  
Adomian Decomposition ◽  
Nonlinear Boundary Value ◽  
Beam Type ◽  
Two Parameter

AbstractNonlinear boundary value problems arise frequently in physical and mechanical sciences. An effective analytic approach with two parameters is first proposed for solving nonlinear boundary value problems. It is demonstrated that solutions given by the two-parameter method are more accurate than solutions given by the Adomian decomposition method (ADM). It is further demonstrated that solutions given by the ADM can also be recovered from the solutions given by the two-parameter method. The effectiveness of this method is demonstrated by solving some nonlinear boundary value problems modeling beam-type nano-electromechanical systems.

A Thermo-Viscoelastic Analysis and Reliability Evaluation for a Single-Sided CSP

2005 ◽  
Author(s):  
Hideo Koguchi ◽  
Mirai Ishida ◽  
Kazuto Nishida ◽  
Tomoaki Kuroishi
Keyword(s):  
Normal Stress ◽  
Viscoelastic Properties ◽  
Normal Stresses ◽  
Layered Plate ◽  
Heat Cycle ◽  
Viscoelastic Analysis ◽  
Chip Size ◽  
Properties Of Materials ◽  
Rigid Walls ◽  
Gold Bump

In the present paper, a reliability of a single-sided chip-size package (CSP) manufactured using a non-conductive adhesive stud bump direct interconnection method is investigated. The reliability of the CSP is closely related with normal stress between an IC chip and a gold bump. Total normal stress can be decomposed into two parts, deflection related and thermal expansion related. The deflection for a three-layered plate, which is taken into account viscoelastic properties for the resin-sealed sheet and the substrate, respectively, is calculated and compared with experimental results on the deflection of the single-sided CSP. A relationship between the normal stress and the curvature derived from deflection is deduced. Through the use of this relationship, the variation of normal stress with the heat cycle is obtained considering the viscoelastic properties of materials. Furthermore, a relaxation behavior for the thermal stress in the resin-sealed sheet between two rigid walls considering its viscoelastic property is investigated. Summing up normal stresses for each calculation yields the normal stress between the IC and the bump. A relationship between the normal stress and the life of single-sided CSP is investigated for heat cycle. The life in experiment can be explained by the relaxation in the normal stress and the amplitude of the normal stress.

On the Applicability of Sneddon's Solution for Interpreting the Indentation of Nonlinear Elastic Biopolymers

2014 ◽  
Vol 81 (9) ◽  
Author(s):  
Man-Gong Zhang ◽  
Jinju Chen ◽  
Xi-Qiao Feng ◽  
Yanping Cao
Keyword(s):  
Elastic Properties ◽  
Viscoelastic Properties ◽  
Contact Theory ◽  
Elastic Contact ◽  
Flat Punch ◽  
Linear Elastic ◽  
Contact Models ◽  
Properties Of Materials ◽  
Nonlinear Elastic ◽  
Viscoelastic Contact

Indentation has been widely used to characterize the mechanical properties of biopolymers. Besides Hertzian solution, Sneddon's solution is frequently adopted to interpret the indentation data to deduce the elastic properties of biopolymers, e.g., elastic modulus. Sneddon's solution also forms the basis to develop viscoelastic contact models for determining the viscoelastic properties of materials from either conical or flat punch indentation responses. It is worth mentioning that the Sneddon's solution was originally proposed on the basis of linear elastic contact theory. However, in both conical and flat punch indentation of compliant materials, the indented solid may undergo finite deformation. In this case, the extent to which the Sneddon's solution is applicable so far has not been systematically investigated. In this paper, we use the combined theoretical, computational, and experimental efforts to investigate the indentation of hyperelastic compliant materials with a flat punch or a conical tip. The applicability of Sneddon's solutions is examined. Furthermore, we present new models to determine the elastic properties of nonlinear elastic biopolymers.

Phytotoxic Interaction Studies – Techniques for Evaluation and Presentation of Results

Weed Science ◽  
1981 ◽  
Vol 29 (2) ◽  
pp. 147-155 ◽  
Author(s):  
R. G. Nash
Keyword(s):  
Growth Response ◽  
Statistical Significance ◽  
Multiple Regression Equation ◽  
Parameter Method ◽  
Regression Estimate ◽  
Pesticide Concentration ◽  
Response Data ◽  
The Individual ◽  
Multiplicative Models ◽  
Two Parameter

Two or more pesticides together may produce a growth response in plants that is not predictable by their individual or independent toxicities. This unpredicted (dependent) response results from an interaction, a concept that usually is not easily interpreted. Dependent responses are further complicated by the fact that they can be either synergistic or antagonistic. Several methods exist for identifying and measuring phytotoxic interactions. Nearly all methods have certain shortcomings, however. Additive and multiplicative models (mathematical expressions) are the two basic approaches to determining pesticide interactions. The two-parameter, isobole, and calculus methods axe additive; whereas, Colby and regression estimate are multiplicative models. Regression estimate analysis considers deviations due to experimental errors, and a statistical significance can be attached to the interaction magnitude, thereby overcoming the deficiencies of the Colby method, but both methods seem to be limited to response data in which the combined pesticide concentration is the sum of the individual pesticide concentrations. The two-parameter method seems to be limited to response data in which the combined concentration is equal to the individual pesticide concentration and to response data in which a pesticide concentration necessary to produce a 50% of control value is interpolated rather than extrapolated. The calculus method is a mathematical expression of the growth response, and interaction is measured by derivation of the equation obtained. The calculus method is difficult to interpret and has a major weakness because it depends upon the multiple regression equation of the observed data. The regression estimate method is recommended as a reasonable approach to interpretation of interaction type data, with a SAS language computer program available from the author.

A Two-Parameter Method to Monitor and Characterize Tool Wear in End Milling Inconel 718

2012 ◽  
Author(s):  
W. Li ◽  
Y. B. Guo
Keyword(s):  
Tool Wear ◽  
Inconel 718 ◽  
Elevated Temperatures ◽  
Flank Wear ◽  
End Milling ◽  
Parameter Method ◽  
Manufacturing Cost ◽  
Cnc Machine ◽  
Coated Carbide ◽  
Two Parameter

Inconel 718 is among the most widely used superalloys in many industries. It is often used in very harsh conditions such as jet engines, combustors and nuclear reactors due to its high strength at elevated temperatures, high oxidation and corrosion resistance. Machining superalloy Inconel 718 has always been a challenging task due to its poor machinability including rapid work hardening, low thermal conductivity, and relatively short cutting tool life. The fast tool wear during cutting Inconel 718 results in longer production time, deteriorated surface integrity, and higher manufacturing cost. In this paper, an on-line optical tool monitoring system integrated with a CNC machine tool has been developed to examine tool wear evolutions in end milling Inconel 718 with PVD (Ti, Al) N/TiN-coated carbide insert. Three basic types of tool wear: flank wear, nose wear, and crater wear were examined and analyzed. A two-parameter method has been proposed to evaluate both flank wear and nose wear vs. cutting time.

Failure Assessment Curves (FACs) in Japanese FFS Code, HPIS Z101 Level 2

2006 ◽  
Author(s):  
Shinji Konosu
Keyword(s):  
High Pressure ◽  
Ferritic Steel ◽  
Carbon Steels ◽  
Parameter Method ◽  
Ferritic Steels ◽  
Failure Assessment ◽  
Interaction Factors ◽  
Level 1 ◽  
Level 2 ◽  
Two Parameter

The High Pressure Institute of Japan has prescribed the Japanese FFS code, HPIS Z101 Level 1, which can evaluate a crack-like flaw without an extensive knowledge of fracture mechanics. Level 2 is currently being studied and will also be prescribed. In HPIS Z101 Level 2, a two-parameter method (FAD: Failure Assessment Diagram) will be adopted. This paper reveals that FACs dependent on the type of materials should be specified. Kr-Lr relations calculated from experimentally obtained Ramberg-Osgood constants of several steels are compared with the FACs of BS7910 Level 2A & API 579 Level 2, R6 Option 1 and ASME N494-3. It is found that the FAC of ferritic steel in ASME N494-3 is pertinent to carbon steels with a marked yield point plateau while the FAC of BS7910 Level 2A & API 579Level 2 is suitable for ferritic steels other than carbon steels such as 0.5Mo, 2.25Cr-1Mo and 2.25Cr-1Mo-0.25V steels. Further, cut-off values dependent on the strength of the material and the plasticity interaction factors for the FAC of carbon steels are proposed.

Sign in / Sign up

Export Citation Format

Share Document