Composite Materials with the Coating to Detect Barely Visible Impact Based on the Retroreflective Film

2021 ◽  
Vol 316 ◽  
pp. 949-954
Author(s):  
Olga Buslaeva ◽  
Sergei Sapozhnikov
Keyword(s):  
Composite Materials ◽  
Contact Pressure ◽  
Residual Strength ◽  
Experimental Studies ◽  
New Method ◽  
Composite Specimen ◽  
Dark Spot ◽  
Spot Diameter ◽  
Three Point Bending ◽  
Strength And Stiffness

A new method of indicating contact damage of composite materials, using a polymer retroreflective film (PRF) with micro-prisms, is proposed. Impact contact action leads to deformation of microprisms and with directed lighting allows seeing the place of impact in the form of a dark spot. In experimental studies, using STEF fibreglass as an example, the dependences of the spot diameter on the contact pressure up to 530 MPa were studied. An assessment of the residual strength and stiffness of a composite specimen-beam with a contact defect was obtained with three-point bending. It is shown that, during bending, the strength of STEF with contact defects decreases from 615 to 386 MPa. The data obtained allow to assess the danger of contact pressure by the known diameter of the dark spot on the PRF.

Predict how long the strength and stiffness of wood constructional composite material

10.12737/4960 ◽  
2014 ◽  
Vol 7 (1) ◽  
pp. 76-79 ◽  
Author(s):  
Стородубцева ◽  
Tamara Storodubtseva
Keyword(s):  
Composite Material ◽  
Composite Materials ◽  
Experimental Studies ◽  
New Method ◽  
Wood Construction ◽  
Strength And Stiffness ◽  
Transportation Facilities

The paper deals with a new method of predicting the durability of wood-construction onnyh composite materials that are used in industrial and transportation facilities, undergoes aggressive influences of different environments. The method is based on experimental studies of creep processes of these materials.

CORRELATION DEPENDENCES OF THE BENDING STRENGTH OF POLYMER COMPOSITE MATERIALS MODIFIED IN A MICROWAVE ELECTROMAGNETIC FIELD ON THE MOISTURE CONTENT DURING EXPOSURE IN FULL-SCALE CONDITIONS

2021 ◽  
pp. 3-9
Author(s):  
I. V. Zlobina ◽  
I. S. Katsuba
Keyword(s):  
Electromagnetic Field ◽  
Composite Materials ◽  
Carbon Fiber ◽  
Moisture Content ◽  
Bending Strength ◽  
Climatic Factors ◽  
Experimental Studies ◽  
Three Point Bending ◽  
Treated Carbon ◽  
Control Samples

Experimental studies of the influence of external climatic factors, taking into account exposure, on the change in the bending strength of control and microwave – treated carbon and fiberglass samples in the cured state were performed. An increase in the limit stresses of three – point bending of experimental carbon fiber samples compared to the control ones was found by 7…12 %, and fiberglassby 4…7 %. It is shown that with an increase in exposure to 14 months, the strength of control samples of carbon and fiberglass decreases by an average of 10 %. At the same time, the strength of the prototypes is reduced only by 4.4 %. With an increase in the moisture content of both control and experimental samples, a decrease in their strength is observed. In this case, the linear correlation is average (from– 0.44 to – 0.615). It is established that for experimental samples, the influence of the amount of absorbed moisture on the strength is manifested to a much lesser extent. For carbon fiber, the reduction is 16.6 %, for fiberglass – 12 %.

Development of a mathematical model to analyze residual strength of composites after low-velocity impact

2018 ◽  
Vol 53 (8) ◽  
pp. 738-745 ◽  
Author(s):  
Camila Medeiros Dantas de Azevedo ◽  
Rayane Dantas da Cunha ◽  
Raimundo Carlos Silverio Freire Junior ◽  
Wanderley Ferreira de Amorim Junior
Keyword(s):  
Residual Strength ◽  
Composite Laminates ◽  
Repair Process ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
Three Point Bending ◽  
Compression After Impact ◽  
Strength And Stiffness ◽  
The Impact

This study aimed to develop a model to analyze the residual strength of composites after low-velocity impact, using three-point bending and compression after impact tests. Two types of composite laminates with an orthophthalic polymer matrix were used: one reinforced with bidirectional E-glass fabric and the other reinforced with bidirectional Kevlar-49 fabric. To that end, an equation was developed to assess loss of strength and stiffness after impact at different distances from the impact point, and this equation was not found in any previously searched article. The results demonstrate that the laminate based in glass fiber is more appropriate for the repair process.

One-Dimensional Contact Pressure Distribution of Radial Tires in Motion

1995 ◽  
Vol 23 (2) ◽  
pp. 116-135 ◽  
Author(s):  
H. Shiobara ◽  
T. Akasaka ◽  
S. Kagami ◽  
S. Tsutsumi
Keyword(s):  
Pressure Distribution ◽  
Contact Pressure ◽  
Experimental Studies ◽  
Rolling Resistance ◽  
Leading Edge ◽  
Forward Direction ◽  
Contact Pressure Distribution ◽  
Support Ring ◽  
One Dimensional ◽  
Lowered Pressure

Abstract The contact pressure distribution and the rolling resistance of a running radial tire under load are fundamental properties of the tire construction, important to the steering performance of automobiles, as is well known. Many theoretical and experimental studies have been previously published on these tire properties. However, the relationships between tire performances in service and tire structural properties have not been clarified sufficiently due to analytical and experimental difficulties. In this paper, establishing a spring support ring model made of a composite belt ring and a Voigt type viscoelastic spring system of the sidewall and the tread rubber, we analyze the one-dimensional contact pressure distribution of a running tire at speeds of up to 60 km/h. The predicted distribution of the contact pressure under appropriate values of damping coefficients of rubber is shown to be in good agreement with experimental results. It is confirmed by this study that increasing velocity causes the pressure to rise at the leading edge of the contact patch, accompanied by the lowered pressure at the trailing edge, and further a slight movement of the contact area in the forward direction.

The Mechanical Properties of Organic Modified Epoxy Resin

2020 ◽  
Vol 43 (3) ◽  
pp. 10-14
Author(s):  
Georgel MIHU ◽  
Claudia Veronica UNGUREANU ◽  
Vasile BRIA ◽  
Marina BUNEA ◽  
Rodica CHIHAI PEȚU ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Epoxy Resin ◽  
Epoxy Matrix ◽  
Epoxy Resins ◽  
Mechanical Tests ◽  
Organic Modification ◽  
Three Point Bending ◽  
Modified Epoxy

Epoxy resins have been presenting a lot of scientific and technical interests and organic modified epoxy resins have recently receiving a great deal of attention. For obtaining the composite materials with good mechanical proprieties, a large variety of organic modification agents were used. For this study gluten and gelatin had been used as modifying agents thinking that their dispersion inside the polymer could increase the polymer biocompatibility. Equal amounts of the proteins were milled together and the obtained compound was used to form 1 to 5% weight ratios organic agents modified epoxy materials. To highlight the effect of these proteins in epoxy matrix mechanical tests as three-point bending and compression were performed.

A new method of manufacturing products from polymeric composite materials

2020 ◽  
Author(s):  
D. A. Negrov ◽  
E. N. Eremin ◽  
A. A. Novikov ◽  
V. Yu. Putintsev
Keyword(s):  
Composite Materials ◽  
Polymeric Composite ◽  
New Method ◽  
Polymeric Composite Materials

An Introduction to the Impact Behaviour of Polymer Composites Using Simplified Beam Models

1998 ◽  
Vol 26 (2) ◽  
pp. 89-110 ◽  
Author(s):  
R. A. W. Mines
Keyword(s):  
Composite Materials ◽  
Undergraduate Students ◽  
Progressive Collapse ◽  
Structural Response ◽  
Sandwich Beams ◽  
Three Point Bending ◽  
The Past ◽  
Structural Case ◽  
The University ◽  
The Impact

The paper describes a final-year undergraduate course that has been taught at the University of Liverpool for the past three years. The main aims of the course are to introduce the student to the design of structures using multi-component (composite) materials and to the performance of such structures under impact loading. Given the complexity of generalized composite behaviour and of structural crashworthiness, a simple structural case is considered, namely, a beam subject to three-point bending. A feature of the course is that not only is linear structural response considered but also non-linear (progressive) structural collapse is covered. The course is split into four parts, namely: (i) analysis of composite laminae, (ii) analysis of laminated beams, (iii) local and global effects in sandwich beams, and (iv) post-failure and progressive collapse of sandwich beams. Static and impact loadings are considered. Comments are made on how the theories are simplified and communicated to the undergraduate students.

Effect of Wood Filler Concentration on Physical and Mechanical Properties of PLA-Based Composites

2021 ◽  
Vol 887 ◽  
pp. 110-115
Author(s):  
G.A. Sabirova ◽  
R.R. Safin ◽  
N.R. Galyavetdinov
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Composite Materials ◽  
Impact Strength ◽  
Wood Flour ◽  
Experimental Studies ◽  
Physical And Mechanical Properties ◽  
Filler Concentration ◽  
High Concentration

This paper presents the findings of experimental studies of the physical and mechanical properties of wood-filled composites based on polylactide (PLA) and vegetable filler in the form of wood flour (WF) thermally modified at 200-240 °C. It also reveals the dependence of the tensile strength, impact strength, bending elastic modulus, and density of composites on the amount of wood filler and the temperature of its thermal pre-modification. We established that an increase in the concentration of the introduced filler and the degree of its heat treatment results in a decrease of the tensile strength, impact strength and density of composite materials, while with a lower binder content, thermal modification at 200 °C has a positive effect on bending elastic modulus. We also found that 40 % content of a wood filler heated to 200 °C is sufficient to maintain relatively high physical and mechanical properties of composite materials. With a higher content of a wood filler, the cost can be reduced but the quality of products made of this material may significantly deteriorate. However, depending on the application and the life cycle of this product, it is possible to develop a formulation that includes a high concentration of filler.

The Tool’s Optimum Geometry Research for Obtaining Apertures in Semi-Cured Polymer Composite Materials

2021 ◽  
Vol 882 ◽  
pp. 114-120
Author(s):  
Mikhail Andreevich Komkov ◽  
Tatyana Vladimirovna Vasilyeva ◽  
Yuriy Nikolaevich Khokhlov ◽  
Mary Alekseevna Prokhorova
Keyword(s):  
Numerical Modeling ◽  
Composite Materials ◽  
Polymer Composite ◽  
Optimal Shape ◽  
Polymer Composite Materials ◽  
New Method ◽  
Optimum Geometry ◽  
Fibrous Polymer ◽  
Fibrous Polymer Composite

The composite materials features and characteristic defects in the obtaining apertures by machining are considered. A new method for forming apertures in fibrous polymer composite materials is proposed. The optimal shape of a tool for piercing holes is determined. The profiles of the pointed part of the tool are compared using numerical modeling.

scholarly journals FEA and Experimental Studies of Adaptive Composite Materials with SMA Wires

2008 ◽  
Author(s):  
K. Kanas ◽  
C. Lekakou ◽  
N. Vrellos ◽  
Alexander M. Korsunsky
Keyword(s):  
Composite Materials ◽  
Experimental Studies ◽  
Adaptive Composite
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