Thermal Expansion of Elastic-Plastic Composite Materials

1986 ◽  
Vol 53 (4) ◽  
pp. 737-743 ◽  
Author(s):  
G. J. Dvorak
Keyword(s):  
Composite Materials ◽  
Heterogeneous Media ◽  
Moisture Absorption ◽  
Thermal Strain ◽  
Local Fields ◽  
Mechanical Stiffness ◽  
Plastic Composite ◽  
Decomposition Procedure ◽  
Concentration Factors ◽  
Binary Composite

Exact relationships are derived between instantaneous overall thermal stress or strain vectors and instantaneous overall mechanical stiffness or compliance, for two binary composite systems in which one of the phases may deform plastically. Also, the local instantaneous thermal strain and stress concentration factors are related in an exact way to the corresponding mechanical concentration factors. The results depend on instantaneous thermoelastic constants and volume fractions of the phases. They are found for fibrous composites with two distinct elastically isotropic or transversely isotropic phases, and for any binary composite with elastically isotropic phases. The results indicate that in the plastic range the thermal and mechanical loading effects are coupled even if the phase properties do not depend on changes in temperature. The derivation is based on a novel decomposition procedure which shows that spatially uniform elastic strain fields can be created in certain heterogeneous media by superposition of uniform phase eigenstrains with local strains, caused by piecewise uniform stress fields which are in equilibrium with prescribed surface tractions. The method is extended to discretized microstructures, and also to the analysis of moisture absorption and phase transformation effects on overall response and on local fields in the two composite materials.

Thermal Expansion of Three-Phase Composite Materials

1989 ◽  
Vol 56 (2) ◽  
pp. 418-422 ◽  
Author(s):  
George J. Dvorak ◽  
Tungyang Chen
Keyword(s):  
Thermal Expansion ◽  
Heterogeneous Media ◽  
Transversely Isotropic ◽  
Local Fields ◽  
Stress Fields ◽  
Cylindrical Shape ◽  
Thermal Expansion Coefficients ◽  
Decomposition Procedure ◽  
Transverse Geometry ◽  
Expansion Coefficients

Exact expressions are found for overall thermal expansion coefficients of a composite medium consisting of three perfectly-bonded transversely isotropic phases of cylindrical shape and arbitrary transverse geometry. The results show that macroscopic thermal expansion coefficients depend only on the thermoelastic constants and volume fractions of the phases, and on the overall compliance. The derivation is based on a decomposition procedure which indicates that spatially uniform elastic strain fields can be created in certain heterogeneous media by superposition of uniform phase thermal strains with local strains caused by piecewise uniform stress fields, which are in equilibrium with prescribed surface tractions. The procedure also allows evaluation of thermal stress fields in the aggregate in terms of known local fields caused by axisymmetric overall stresses. Finally, averages of local fields are found with the help of known mechanical stress and strain concentration factors.

Thermal strain analysis of composite materials by electronic speckle pattern interferometry

2000 ◽  
Vol 14 (5) ◽  
pp. 477-482 ◽  
Author(s):  
Koung Suk Kim ◽  
Wan Shik Jang ◽  
Myung Seak Hong ◽  
Ki Soo Kang ◽  
Hyun Chul Jung ◽  
...  
Keyword(s):  
Composite Materials ◽  
Speckle Pattern ◽  
Thermal Strain ◽  
Strain Analysis ◽  
Electronic Speckle Pattern Interferometry

Universal Relations in Piezoelectric Composites With Eigenstress and Polarization Fields, Part I: Binary Media—Local Fields and Effective Behavior

1993 ◽  
Vol 60 (2) ◽  
pp. 265-269 ◽  
Author(s):  
Y. Benveniste
Keyword(s):  
Spontaneous Polarization ◽  
Electric Field Intensity ◽  
Local Fields ◽  
Composite Media ◽  
Piezoelectric Composites ◽  
Arbitrary Phase ◽  
Electromechanical Loading ◽  
Piezoelectric Behavior ◽  
Binary Composite ◽  
Effective Constants

Binary composite media of arbitrary phase geometry are considered. The constituent phases have general anisotropic piezoelectric behavior and contain constant eigenstress and spontaneous polarization fields. An electromechanical loading of the composite aggregate is found which results in uniform strain and electric field intensity throughout the solid. The existence of these uniform fields is used to derive exact universal relations between the local fields as well as between the effective constants of the composite aggregate.

Mechanical Properties of 3D-Printed Wood-Plastic Composites

2018 ◽  
Vol 777 ◽  
pp. 499-507 ◽  
Author(s):  
Ossi Martikka ◽  
Timo Kärki ◽  
Qing Ling Wu
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
3D Printing ◽  
Impact Strength ◽  
Polylactic Acid ◽  
Wood Plastic Composite ◽  
Wood Plastic Composites ◽  
Plastic Composite ◽  
Plastic Composites ◽  
3D Printed

3D printing has rapidly become popular in both industry and private use. Especially fused deposition modeling has increased its popularity due to its relatively low cost. The purpose of this study is to increase knowledge in the mechanical properties of parts made of wood-plastic composite materials by using 3D printing. The tensile properties and impact strength of two 3D-printed commercial wood-plastic composite materials are studied and compared to those made of pure polylactic acid. Relative to weight –mechanical properties and the effect of the amount of fill on the properties are also determined. The results indicate that parts made of wood-plastic composites have notably lower tensile strength and impact strength that those made of pure polylactic acid. The mechanical properties can be considered sufficient for low-stress applications, such as visualization of prototypes and models or decorative items.

On transformation strains and uniform fields in multiphase elastic media

1992 ◽  
Vol 437 (1900) ◽  
pp. 291-310 ◽  
Keyword(s):  
Concentration Factor ◽  
Elastic Stiffness ◽  
Local Fields ◽  
Influence Functions ◽  
Elastic Solids ◽  
Two Phase ◽  
General Properties ◽  
Multiphase Systems ◽  
Concentration Factors ◽  
Mechanical Influence

The effect of local eigenstrain and eigenstress fields, or transformation fields, on the local strains and stresses is explored in multiphase elastic solids of arbitrary geometry and material symmetry. The residual local fields caused by such transformation fields are sought in terms of certain transformation influence functions and transformation concentration factor tensors. General properties of these functions and concentration factors, and their relation to the analogous mechanical influence functions and concentration factors, are established, in part, with the help of uniform strain fields in multiphase media. Specific estimates of the transformation concentration factor tensors are evaluated by the self-consistent and Mori-Tanaka methods. It is found here that although the two methods use different constraint tensors in solutions of the respective dilute problems, their estimates of the mechanical, thermal, and transformation concentration factor tensors, and of the overall stiffness of multiphase media have a similar structure. Proofs that guarantee that these methods comply with the general properties of the transformation influence functions, and provide diagonally symmetric estimates of the overall elastic stiffness, are given for two-phase and multiphase systems consisting of, or reinforced by, inclusions of similar shape and alignment. One of the possible applications of the results, in analysis of overall instantaneous properties and local fields in inelastic composite materials, is described in the following paper.

Application of processing fiber-plastic composite washing

2021 ◽  
Vol 2021 (23) ◽  
pp. 214-224
Author(s):  
Artur Onyshchenko ◽  
◽  
Mykola Garkusha ◽  
Оlena Deli ◽  
◽  
...  
Keyword(s):  
Composite Materials ◽  
Operating Conditions ◽  
Structural Elements ◽  
Washing Machine ◽  
Normative Documents ◽  
Plastic Composite ◽  
Fiber Plastic ◽  
Fiberglass Composite ◽  
Composite Bridge

Introduction. Innovative, new materials are increasingly used in transport construction, among which composite materials are becoming widespread.Small bridges and elements of large bridges, such as roadway slabs, pavements, railings, composite reinforcement, reinforcement elements, are made of composite materials.Recently, the use of polymer composite materials for the manufacture of lightly loaded structural elements of transport structures, such as lighting poles, drainage trays, railings.Much attention should be paid to the fiberglass composite railing, which has a number of advantages over traditional metal fencing. Unfortunately, at present there are no clearly defined in Ukraine regulations on fiberglass composite fencing, so this topic is relevant and necessary for the transport industry.Problem Statement. From the literature analysis it is established that the railings of highways and sidewalks are in difficult operating conditions, are constantly exposed to aggressive environments - water, chemicals, salts.Goal. Increasing the durability of the railing by using new materials.Results. The analysis of production of a fiberglass profile is carried out. On the basis of the conducted researches the general requirements to a protection of fiberglass composite washing machine are established. On the basis of the current normative documents the classification of a protection on a place of installation, type of filling of a skeleton, a method of fastening of risers is developed. The paper presents the main parameters and dimensions of the fence. Material requirements are set. Methods of control of a protection with establishment of a technique of test of a protection on resistance to action of horizontal and vertical loadings are developed. Recommendations on installation and installation of a protection of fiberglass composite washing machine are offered.Conclusions. The research results were used in the development of technical conditions for the protection of fiberglass composite washing machine.Keywords: road, composite, bridge, fencing, profile, fiberglass, artificial construction

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