Determination of the Matrix of Rigidity of a Composite Material by the Combination of Speckle Interferometry and Ultrasonic Measurements

2006 ◽  
Vol 3-4 ◽  
pp. 155-160
Author(s):  
Lofti Toubal ◽  
Moussa Karama ◽  
B. Lorrain
Keyword(s):  
Composite Material ◽  
Plane Deformation ◽  
Composite Plates ◽  
Speckle Interferometry ◽  
Structural Work ◽  
Ultrasonic Measurements ◽  
Out Of Plane ◽  
The Matrix ◽  
Electronic Speckle Interferometry

The characterisation of composite plates used in structural work in the field of aeronautics is approached by associating ultrasound and speckle interferometry measurements. The reduced thickness of the specimens does not allow for gauge instrumentation to measure out-of plane deformation. A system was therefore used which makes it possible to obtain the cartography of the deformations in and out of-plane. This paper describes an application of electronic speckle interferometry in the measurement of through thickness deformation in composites.

Research of stamping of unequal channel bars. Part 3. Force parameters and shape change of the billet when extruding channels. 2. Determination of the extrusion force, maximum pressure on the matrix wall and the heights of the walls, taking into account the elastic deformation jf the matrix

2021 ◽  
pp. 63-69
Author(s):  
A.L. Vorontsov
Keyword(s):  
Plastic Flow ◽  
Elastic Deformation ◽  
Shape Change ◽  
Plane Deformation ◽  
Maximum Pressure ◽  
Extrusion Force ◽  
System Of Equations ◽  
The Matrix ◽  
Theory Of Plastic Flow

On the basis of the system of equations of the theory of plastic flow, the forces, the maximum pressure on the wall of the matrix and the heights of the obtained walls when extruding channels are determined, taking into account the elastic deformation of the matrix. Keywords: die forging, extrusion, misalignment, punch, matrix, plane deformation, stresses. [email protected]

scholarly journals Approaches to the evaluation of the mechanical properties of single-layer composite plates made of recyclable polymeric and protein materials

2020 ◽  
Author(s):  
Ion Durbaca ◽  
Radu Iatan ◽  
Elena Surdu ◽  
Dana-Claudia Farcas-Flamaropol
Keyword(s):  
Composite Material ◽  
Mechanical Characteristics ◽  
Single Layer ◽  
Composite Plates ◽  
Structural Elements ◽  
Efficient Design ◽  
Protein Matrix ◽  
Layer Composite ◽  
Definition Of

This paper deals with the theoretical and experimental mechanical characteristics of composite plates obtained from recyclable polymer and protein matrix and fibrous reinforcement. The definition of the theoretical model of the monolayer composite material with its structural elements and the physical-mechanical evaluation of its characteristics leads to the optimal and efficient design and use of all products made of such materials. By the theoretical and experimental determination of the mechanical characteristics that define the properties of the composite material, it can be decided on its use in specific industrial technical applications.

Homogenization of Out-of-Plane Loaded Random Plates

2010 ◽  
Vol 638-642 ◽  
pp. 2766-2771
Author(s):  
Karam Sab
Keyword(s):  
Composite Material ◽  
Boundary Conditions ◽  
Boundary Problem ◽  
Representative Volume Element ◽  
Plane Deformation ◽  
Infinite Plate ◽  
Volume Element ◽  
Stress And Strain ◽  
Strain Fields ◽  
Out Of Plane

The homogenization of elastic periodic plates is as follows: The 3D heterogeneous body is replaced by a homogeneous Love-Kirchhoff plate whose stiffness constants are computed by solving an auxiliary boundary problem on a 3D unit cell that generates the plate by periodicity in the in-plane directions. In the present study, a generalization of the above mentioned approach is presented for the random case. The homogenized bending stiffness and the moduli for in-plane deformation of a plate cut from a block of composite material, considered to be a statistically uniform random material in the in-plane directions, are defined in three equivalent manners: a) the first definition considers statistically invariant stress and strain fields in the infinite plate. In the second and third definitions, a finite representative volume element of the plate is submitted to suitable b) kinematically uniform boundary conditions and c) statically uniform boundary conditions. The relationships between these three definitions are studied and bounds are derived.

DETERMINATION OF THE POLYMERIZATION DEGREE OF THE MATRIX OF POLYMER COMPOSITE MATERIAL USING ULTRASONIC METHOD

2019 ◽  
Vol 85 (4) ◽  
pp. 33-39
Author(s):  
Victor V. Murashov ◽  
Valery M. Aleksashin ◽  
Konstantin S. Mishurov
Keyword(s):  
Composite Material ◽  
Kinetic Parameters ◽  
Polymer Composite ◽  
Ultrasonic Method ◽  
Acoustic Method ◽  
Degree Of Polymerization ◽  
Polymer Composite Material ◽  
Ultrasonic Vibrations ◽  
The Matrix

The results of studying the efficiency of the laser-acoustic method of ultrasonic testing in determination of the degree of polymerization of the matrix of polymer composite material (PCM) are presented. We have studied the PCM samples used for manufacturing integrated structures. It is shown that excessive degree of polymerization of the preformed blanks leads to a decrease in the strength of connection of the structural elements and precludes obtaining the desired shape and geometric dimensions of the product. We developed fundamentally new diagnostic parameters, which are characterized by high reliability and accuracy of determination. To forecast sample curing regimes with given values of the degree of transformation, the reaction kinetics was analyzed using differential scanning calorimetry Experimental results used for calculation of the kinetic parameters were obtained on a thermoanalytical complex DSC 1 (Switzerland). The kinetic parameters of polymerization and degree of binder curing in plastics were determined by the thermal effect of the reaction. It is shown that when determining the degree of polymerization of a PCM matrix by an ultrasonic method (laser-acoustic method of exciting ultrasonic vibrations), the product of attenuation of the bottom signal of longitudinal ultrasonic vibrations by the signal round-trip time and energy of the structural noise (thus taking into account the porosity of the material), can be used as reliable parameters of diagnostics. The proposed method provides higher accuracy compared to other methods used for control of the degree of polymerization.

Three-dimensional nanoprepreg and nanostitched aramid/phenolic multiwall carbon nanotubes composites: Experimental determination of in-plane shear

2019 ◽  
Vol 53 (28-30) ◽  
pp. 4077-4096 ◽  
Author(s):  
Kadir Bilisik ◽  
Gulhan Erdogan ◽  
Erdal Sapanci ◽  
Sila Gungor
Keyword(s):  
Carbon Nanotubes ◽  
Three Dimensional ◽  
Multiwall Carbon Nanotubes ◽  
Nano Composites ◽  
Plane Shear ◽  
Pull Out ◽  
Out Of Plane ◽  
The Matrix ◽  
Multiwall Carbon

In-plane shear of nanostitched three-dimensional para-aramid/phenolic composites were experimentally investigated. Adding the nanostitched fiber into nanoprepreg para-aramid fabric preform composites slightly improved their shear strengths. The carbon-stitched composite exhibited comparatively better performance compared to the para-aramid stitched composite probably due to well bonding between carbon fiber and phenolic resin. The stitched nano composites had mainly matrix breakages and micro shear hackles in the matrix; matrix debonding and filament pull-out in the composite interface; fibrillar peeling and stripping on the filaments due to angular deformation. This mechanism probably prohibited extensive interlaminar opening in the nanostitched composites. The result exhibited that the introducing of the nano stitched fiber where multiwall carbon nanotubes were transferred to the out-of-plane of the base structure enhanced its transverse fracture as a form of confined delamination area. Therefore, the damaged tolerance properties of the stitched nano composites were enhanced compared to the base.

Elastic Constants Determination of Composite Plates Using Measured Strains

2019 ◽  
Vol 943 ◽  
pp. 87-91
Author(s):  
Chien Yang Huang ◽  
T.Y. Kam
Keyword(s):  
Composite Material ◽  
Elastic Constants ◽  
Composite Plates ◽  
Uniaxial Tensile ◽  
Optimization Approach ◽  
Load Testing ◽  
Uniaxial Tensile Testing ◽  
Theoretical Predictions ◽  
Strain Components

A strain-based elastic constant identification method is proposed to determine the elastic constants of fiber-reinforced composite rectangular laminates using three measured strains of the plates subjected to uniaxial load testing. In the proposed method, the measured normal strains in 0°, and 45°, and 90° directions, respectively, of the plate made of one composite material subjected to uniaxial tensile testing are used to identify four elastic constants of the constituent composite material via a two-level optimization approach. The objective function used for constructing the two-level optimization problem consists of the sum of the differences between the experimental and theoretical predictions of the three strain components and a strain restraining function, which is used to help even up the effects of the measured strains on the identified elastic constants. The accuracy of the proposed method has been verified via an experimental approach.

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