Inflation Characteristics of Unvulcanized Gum and Compounded Rubber Sheets

1986 ◽  
Vol 59 (2) ◽  
pp. 315-327 ◽  
Author(s):  
Dancheng Kong ◽  
James L. White
Keyword(s):  
Constitutive Equations ◽  
Failure Mechanisms ◽  
Experimental Studies ◽  
Small Deformation ◽  
Rubber Compound ◽  
Basic Study ◽  
Quantitative Measurements ◽  
Vulcanized Rubber ◽  
Strain Relationship ◽  
Nonlinear Elastic

Abstract The inflation of rubber compound membranes to fill molds has a long history in rubber processing. There have, however, been few basic experimental studies of this topic. This free inflation of vulcanized rubber sheets was studied by Treloar and Rivlin and Saunders during the 1940's and 50's where it was used to investigate the form of the stress-strain relationship. Rivlin and Saunders sought to fit nonlinear elastic constitutive equations to data obtained at small inflation levels. In the early 1970's Denson and his coworkers utilized the inflation of unvulcanized polyisobutylene membranes to apply this as a procedure to evaluate biaxial and planar extensional viscosities. Similar studies were made by Maerker and Schowalter. These studies all involve free inflation of membranes. These studies of inflation of raw gum polyisobutylene sheets only looked at relatively small deformation levels where a hemispherical shape or less was achieved. Failure mechanisms in similarly inflated vulcanized SBR 1502 rubber sheets were described by Dickie and Smith. These authors did not describe the shapes of the inflated sheets. There seem to be no studies of inflation of rubber membranes into molds or useful equivalent studies of molten plastics such as thermoforming. It is the purpose of this paper to present a basic study of the inflation of membranes of various gum and compounded elastomers. We observe the manner in which the membranes freely inflate into air and also the manner in which they fill molds of various shapes. We begin with qualitative considerations but will also present quantitative measurements. Biaxial elongational viscosities have been estimated.

Vibrations of Foundations Interacting With Subsoil Experimental Studies and BE Calculations

1991 ◽  
Author(s):  
L. Gaul
Keyword(s):  
Boundary Element Method ◽  
Dynamic Response ◽  
Surface Waves ◽  
Boundary Element ◽  
Constitutive Equations ◽  
Experimental Studies ◽  
Boundary Elements ◽  
Experimental Techniques ◽  
Embedded Structures ◽  
Element Method

Abstract Calculation of the dynamic response of sensitive structures like foundations for vibrating machinery requires to take the interaction with subsoil into account. Structures and soil are discretized by boundary elements and coupled by a substructure technique. Viscoelastic constitutive equations contain fractional time derivatives. Surface waves generated by machine foundations and diffracted by embedded structures and soil inhomogeneities are analyzed by conventional and optoelectronic experimental techniques and calculated by the boundary element method (BEM).

Experimental studies on failure mechanisms of impacted composite plates

1976 ◽  
Vol 9 (3) ◽  
pp. 177-188 ◽  
Author(s):  
C.A. Ross ◽  
N. Cristescu ◽  
R.L. Sierakowski
Keyword(s):  
Failure Mechanisms ◽  
Experimental Studies ◽  
Composite Plates

Constitutive Equations for Tensile and Creep Behavior of a 9 Cr-1 MO Steel

1975 ◽  
Vol 97 (4) ◽  
pp. 258-263
Author(s):  
F. V. Ellis ◽  
J. E. Bynum ◽  
B. W. Roberts
Keyword(s):  
Constitutive Equation ◽  
Test Data ◽  
Constitutive Equations ◽  
Tensile Tests ◽  
Temperature Dependent ◽  
Creep Tests ◽  
Creep Properties ◽  
Hardening Mechanism ◽  
Strain Relationship ◽  
Analysis Computer

This paper describes an investigation of the tensile and creep properties of annealed 9 Cr-1 Mo steel. Tensile tests were conducted at temperatures from 70 to 1050 F while creep tests were conducted at 750, 850, 950, and 1050 F with stresses from 4 to 52 ksi. From the tensile test data, a constitutive equation was developed for the stress-plastic strain relationship. This equation was based on a two-stage hardening mechanism and combined power law and exponential functions. From the creep test data, isochronous stress-strain curves were constructed out to 104 hr. These curves were extrapolated to 105 hr and to lower stresses using a parametric analysis procedure. Additionally, a creep constitutive equation capable of describing the total creep curve, including the tertiary region, was developed. This equation, having three stress and temperature dependent parameters predicted creep curves which were in good agreement with the actual curves. Both the time-independent (tensile) and time-dependent (creep) constitutive equations are suitable for use in finite element stress analysis computer programs.

Constitutive equations for the nonlinear elastic response of rubbers

2006 ◽  
Vol 185 (1-2) ◽  
pp. 31-65 ◽  
Author(s):  
A. D. Drozdov ◽  
J. deClaville Christiansen
Keyword(s):  
Constitutive Equations ◽  
Elastic Response ◽  
Nonlinear Elastic

A Nonlinear Elastic Model for Isotropic Materials With Different Behavior in Tension and Compression

1982 ◽  
Vol 104 (1) ◽  
pp. 26-28 ◽  
Author(s):  
Gianluca Medri
Keyword(s):  
Mechanical Characterization ◽  
Three Dimensional ◽  
Small Deformation ◽  
Stress And Strain ◽  
Elastic Model ◽  
Strain Fields ◽  
Isotropic Materials ◽  
Tension And Compression ◽  
Nonlinear Elastic

This note presents a model suitable for the mechanical characterization of isotropic materials with different behavior in tension and compression. The model has been derived from the nonlinear elastic theory and elaborated to adapt it to the small deformation field; the constitutive relation may reliably correlate stress and strain fields even in three-dimensional elastic problems.

scholarly journals Failure Mechanisms and Parameters of Elastoplastic Deformations of Anchorage in a Damaged Concrete Base under Seismic Loading

Buildings ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 78
Author(s):  
Oleg Kabantsev ◽  
Mikhail Kovalev
Keyword(s):  
Bearing Capacity ◽  
Limit State ◽  
Failure Mechanisms ◽  
Experimental Studies ◽  
Seismic Load ◽  
Embedment Depth ◽  
Concrete Base ◽  
Physical Experiments ◽  
Steel Strength ◽  
Research Findings

The article addresses mechanisms of anchorage failure in a concrete base studied within the framework of physical experiments. The authors investigated the most frequently used types of anchors, such as the cast-in-place and post-installed ones. The anchorages were studied under static and dynamic loading, similar to the seismic type. During the experiments, the post-earthquake condition of a concrete base was simulated. Within the framework of the study, the authors modified the values of such parameters, such as the anchor embedment depth, anchor steel strength, base concrete class, and base crack width. As a result of the experimental studies, the authors identified all possible failure mechanisms for versatile types of anchorages, including steel and concrete cone failures, anchor slippage at the interface with the base concrete (two types of failure mechanisms were identified), as well as the failure involving the slippage of the adhesive composition at the interface with the concrete of the anchor embedment area. The data obtained by the authors encompasses total displacements in the elastic and plastic phases of deformation, values of the bearing capacity for each type of anchorage, values of the bearing capacity reduction, and displacements following multi-cyclic loading compared to static loading. As a result of the research, the authors identified two types of patterns that anchorages follow approaching the limit state: elastic-brittle and elastoplastic mechanisms. The findings of the experimental research allowed the authors to determine the plasticity coefficients for the studied types of anchors and different failure mechanisms. The research findings can be used to justify seismic load reduction factors to be further used in the seismic design of anchorages.

Sign in / Sign up

Export Citation Format

Share Document