scholarly journals Quasi-Static Shear Test of Hybrid Adhesive Bonds Based on Treated Cotton-Epoxy Resin Layer

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2945
Author(s):  
Martin Tichý ◽  
Viktor Kolář ◽  
Miroslav Müller ◽  
Rajesh Kumar Mishra ◽  
Vladimír Šleger ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Strain Difference ◽  
Cyclic Stress ◽  
Cotton Fabrics ◽  
Adhesive Bonds ◽  
Static Tests ◽  
Static Test ◽  
Static Conditions ◽  
Pure Resin

This research evaluates the mechanical properties of hybrid adhesive bonds with various 100% cotton fabrics in static and quasi-static conditions and the influence of alkali surface treatment (NaOH) of the cotton fabrics on the mechanical properties. Biological fibers in polymers are characterized by low wettability with the matrix, which decreases mechanical properties. Adhesive bonds usually operate in cyclic stress, which causes irreversible failure before maximal strength. In this paper, a quasi-static test was used to load the adhesive bonds in 5–50% (192–1951 N) and 5–70% (192–2732 N) intervals with 1000 cycles. The results of SEM analysis showed good wettability of alkali treated cotton fabric with NaOH solution in hybrid adhesive bonds. The static test proved the influence of reinforcing cotton fabrics on shear tensile strength against pure resin, i.e., sample Erik up to 19% on 14.90 ± 1.15 MPa and sample Tera up to 21% on 15.28 ± 1.05 MPa. The adhesive bonds with pure resin did not resist either quasi-static tests. Reinforcing cotton fabrics resisted both quasi-static tests, even shear tensile strength increases up to 10% on 16.34 ± 1.24 MPa for the fabric Erik. The results of strain difference of adhesive bonds with Tera and Erik confirmed that a lower value of the difference during cyclic loading positively influenced the ultimate shear tensile strength.

scholarly journals Quasi-Static Tests of Hybrid Adhesive Bonds Based on Biological Reinforcement in the Form of Eggshell Microparticles

Polymers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1391 ◽  
Author(s):  
Viktor Kolář ◽  
Miroslav Müller ◽  
Rajesh Mishra ◽  
Anna Rudawska ◽  
Vladimír Šleger ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cyclic Loading ◽  
Service Life ◽  
Adhesive Layer ◽  
Maximum Load ◽  
Adhesive Bonds ◽  
Static Tests ◽  
Static Test ◽  
The Matrix ◽  
Positive Effect

The paper is focused on the research of the cyclic loading of hybrid adhesive bonds based on eggshell microparticles in polymer composite. The aim of the research was to characterize the behavior of hybrid adhesive bonds with composite adhesive layer in quasi-static tests. An epoxy resin was used as the matrix and microparticles of eggshells were used as the filler. The adhesive bonds were exposed to cyclic loading and their service life and mechanical properties were evaluated. Testing was performed by 1000 cycles at 5–30% (165–989 N) and 5–70% (165–2307 N) of the maximum load of the filler-free bond in the static test. The results of the research show the importance of cyclic loading on the service life and mechanical properties of adhesive bonds. Quasi-static tests demonstrated significant differences between measured intervals of cyclic loading. All adhesive bonds resisted 1000 cycles of the quasi-static test with an interval loading 5–30%. The number of completed quasi-static tests with the interval loading 5–70% was significantly lower. The filler positively influenced the service life of adhesive bonds at a higher amount of quasi-static tests, i.e., the safety of adhesive bonds increased. The filler had a positive effect on adhesive bonds ABF2, where the strength significantly increased up to 20.26% at the loading of 5–30% against adhesive bonds ABF0. A viscoelasticity characteristic (creep) of the adhesive layer occurred at higher values of loading, i.e., between loading 5–70%. The viscoelasticity behavior did not occur at lower values of loading, i.e., between loading 5–30%.

Effects of Cyclic Stress on the Mechanical Properties of Cultured Collagen Fascicles from the Rabbit Patellar Tendon

2003 ◽  
Vol 125 (6) ◽  
pp. 893-901 ◽  
Author(s):  
Ei Yamamoto ◽  
Susumu Tokura ◽  
Kozaburo Hayashi
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Patellar Tendon ◽  
Control Level ◽  
Quadratic Function ◽  
Peak Stress ◽  
Cyclic Stress ◽  
Original Strength

Effects of cyclic stress on the mechanical properties of collagen fascicles were studied by in vitro tissue culture experiments. Collagen fascicles (approximately 300 μm in diameter) obtained from the rabbit patellar tendon were applied cyclic load at 4 Hz for one hour per day during culture period for one or two weeks, and then their mechanical properties were determined using a micro-tensile tester. There was a statistically significant correlation between tensile strength and applied peak stress in the range of 0 to 5 MPa, and the relation was expressed by a quadratic function. The maximum strength (19.4 MPa) was obtained at the applied peak stress of 1.8 MPa. The tensile strength of fascicles were within a range of control values, if they were cultured under peak stresses between 1.1 and 2.6 MPa. Similar results were also observed in the tangent modulus, which was maintained at control level under applied peak stresses between 0.9 and 2.8 MPa. The stress of 0.9 to 1.1 MPa is equivalent to approximately 40% of the in vivo peak stress which is developed in the intact rabbit patellar tendon by running, whereas that of 2.6 to 2.8 MPa corresponds to approximately 120% of the in vivo peak stress. Therefore, the fascicles cultured under applied peak stresses of lower than 40% and higher than 120% of the in vivo peak stress do not keep the original strength and modulus. These results indicate that the mechanical properties of cultured collagen fascicles strongly depend upon the magnitude of the stress applied during culture, which are similar to our previous results observed in stress-shielded and overstressed patellar tendons in vivo.

Cyclic behaviour of materials

1970 ◽  
Vol 5 (3) ◽  
pp. 185-192 ◽  
Author(s):  
K J Miller
Keyword(s):  
Strain Rate ◽  
Strain Curve ◽  
Cyclic Hardening ◽  
Fatigue Behaviour ◽  
Cyclic Stress ◽  
Cyclic Softening ◽  
Static Tests ◽  
Static Test ◽  
Cyclic Behaviour ◽  
Incremental Step

The effect of strain rate on the cyclic behaviour of two materials is presented. For the material that cyclically hardens (En 32B) a decrease in strain rate decreases the maximum cyclic hardening of the material, whilst for a material that cyclically softens (En 25) a decrease in the rate of deformation increases the maximum cyclic softening. It is concluded that the effect of strain rate on the cyclic stress-strain curve should be more closely studied than the effect of frequency since the frequency may be constant whilst the straining rate may vary considerably in plastically deformed zones. For those zones that suffer low strain rates the inclusion of time-dependent deformation processes can maximize the degree of softening or minimize the degree of hardening, thereby creating a greater localization of the plastic strain which should increase strain-concentration factors. Finally it is argued that it is better to predict fatigue behaviour from an incremental-step high-strain fatigue test on a single specimen than from static-test data. For the same reasons correlations between static tests and fatigue tests should be discouraged, especially for those materials that exhibit marked cyclic softening.

scholarly journals ANALISIS MATERIAL KOMPOSIT BERBASIS SERAT PELEPAH KELAPA SAWIT DAN MATRIKS POLYPROPYLENE SEBAGAI BAHAN PEMBUATAN BUMPER MOBIL

2019 ◽  
Vol 2 (2) ◽  
pp. 15
Author(s):  
Rizal Hanifi ◽  
Gebyar Dewangga ◽  
Kardiman Kasiadi ◽  
Eri Widianto
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Yield Strength ◽  
Physical Properties ◽  
Volume Fraction ◽  
Test Results ◽  
Hot Press ◽  
Static Test ◽  
Failure Simulation ◽  
Simulation Results

Research has been carried out on the analysis of mechanical properties and simulation of composite failure of oil palm midrib fiber polypropylene matrix as car bumpers. This research is expected to provide information on the results of testing the mechanical properties and physical properties and to find out the results of failure simulation in stress analysis based on static test using Inventor Professional 2015 software. Composite boards are made using the hot press method with three variations volume fraction is 20% fiber: 80% matrix, 30% fiber: 70% matrix and 40% fiber: 60% matrix. Characterization of composite physical properties in the form of density, swelling, and water uptake while mechanical properties in the form of tensile testing. Composite physical test results showed that composites made according to JIS A5908 (2003) composite tensile test results showed that the maximum tensile strength obtained at the volume fraction of 40% fiber: 60% matrix with a value of 21.106 MPa, followed by a decrease in tensile strength in volume fraction 30% fiber: 70% matrix and 20% fiber: 80% matrix. Increased tensile strength due to direct orientation of fibers and the addition of fiber composition. Composites are still worth making bumper because the value of tensile strength is no less than the standard bumper which is 8,09 MPa. Next, failure simulation results based on a static test uses three variations of speed, namely 60 km/hr, 80 km/hr and 100 km/hr. The failure simulation results based on the static test of the three speed variations show the value of the von misses stress below the yield strength of the material, then the displacement value that occurs is small and the value of the safety factor produced is above one. From the results of the analysis of composite testing, it shows that the composite has the potential to be a car bumper material.Telah dilakukan penelitian tentang analisis sifat mekanik dan simulasi kegagalan komposit serat pelepah kelapa sawit matriks polypropylene sebagai bumper mobil. Penelitian ini diharapkan dapat memberi informasi hasil pengujian sifat mekanik dan sifat fisis serta mengetahui hasil simulasi kegagalan dalam stress analysis berdasarkan static test menggunakan software Inventor Professional 2015. Papan komposit dibuat menggunakan metode hot press dengan tiga variasi fraksi volume yaitu 20% serat: 80% matriks, 30% serat: 70% matriks dan 40% serat: 60% matriks. Karakterisasi sifat fisis komposit berupa densitas, swelling, dan serapan air sedangkan sifat mekanik berupa pengujian tarik. Hasil pengujian fisis komposit menunjukkan bahwa komposit yang dibuat sesuai dengan klasifikasi JIS A5908. Hasil pengujian tarik komposit menunjukkan bahwa nilai kekuatan tarik maksimal yang paling besar diperoleh pada fraksi volume 40% serat: 60% matriks dengan nilai 21,106 MPa, diikuti penurunan kekuatan tarik pada fraksi volume 30% serat: 70% matriks dan 20% serat: 80% matriks. Meningkatnya kekuatan tarik dikarenakan orientasi serat searah dan penambahan komposisi serat. Komposit masih layak dibuat bumper karena nilai kekuatan tariknya tidak kurang dari standar bumper yaitu 8,09 MPa. Selanjunya, hasil simulasi kegagalan berdasarkan static test menggunakan tiga variasi kecepatan yaitu 60 km/jam, 80 km/jam dan 100 km/jam. Hasil simulasi kegagalan berdasarkan static test dari ketiga variasi kecepatan tersebut menunjukkan nilai von misses stress dibawah nilai yield strength yang dimiliki material, kemudian nilai displacement yang terjadi kecil serta nilai safety factor yang dihasilkan yaitu di atas satu. Dari hasil analisis pengujian komposit tersebut menunjukkan bahwa komposit berpotensi sebagai material bumper mobil

Effects of the Frequency and Duration of Cyclic Stress on the Mechanical Properties of Cultured Collagen Fascicles From the Rabbit Patellar Tendon

2005 ◽  
Vol 127 (7) ◽  
pp. 1168-1175 ◽  
Author(s):  
Ei Yamamoto ◽  
Daisuke Kogawa ◽  
Susumu Tokura ◽  
Kozaburo Hayashi
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Patellar Tendon ◽  
Load Condition ◽  
Peak Stress ◽  
Cyclic Stress ◽  
Control Group ◽  
Significant Difference

The effects of frequency or duration of cyclic stress on the mechanical properties of collagen fascicles were studied by means of in vitro tissue culture experiments. Collagen fascicles of approximately 300μm in diameter were obtained from rabbit patellar tendons. During culture, cyclic stress having the peak stress of approximately 2MPa was applied to the fascicles at 1Hz for 1hour∕day (1Hz-1h group), at 1Hz for 4hours∕day (1Hz-4h group), or at 4Hz for 1hour∕day (4Hz-1h group). The frequency of 4Hz and the duration of 1hour∕day are considered to be similar to those of the in vivo stress applied to fascicles in the intact rabbit patellar tendon. After culture for 1 or 2weeks, the mechanical properties of the fascicles were determined using a micro-tensile tester, and were compared to the properties of non-cultured, fresh fascicles (control group) and the fascicles cultured under no load condition (non-loaded group). The tangent modulus and tensile strength of fascicles in the 4Hz-1h group were similar to those in the control group; however, the fascicles of the 1Hz-1h and 1Hz-4h groups had significantly lower values than those of the control group. There was no significant difference in the tensile strength between the 1Hz-1h and non-loaded groups, although the strength in the 1Hz-4h group was significantly higher than that of the non-loaded group. It was concluded that the frequency and duration of cyclic stress significantly affect the mechanical properties of cultured collagen fascicles. If we apply cyclic stress having the frequency and duration which are experienced in vivo, the biomechanical properties are maintained at control, normal level. Lower frequencies or less cycles of applied force induce adverse effects.

scholarly journals Mechanical Properties of Human Dura Mater in Tension – An Analysis at an Age Range of 2 to 94 Years

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Johann Zwirner ◽  
Mario Scholze ◽  
John Neil Waddell ◽  
Benjamin Ondruschka ◽  
Niels Hammer
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Dura Mater ◽  
Human Head ◽  
Middle Meningeal Artery ◽  
Tensile Tests ◽  
Image Correlation ◽  
Tensile Data ◽  
Static Conditions

Abstract Realistic human head models are of great interest in traumatic brain injury research and in the forensic pathology courtroom and teaching. Due to a lack of biomechanical data, the human dura mater is underrepresented in head models. This study provides tensile data of 73 fresh human cranial dura mater samples retrieved from an area between the anterior middle and the posterior middle meningeal artery. Tissues were adapted to their native water content using the osmotic stress technique. Tensile tests were conducted under quasi-static uniaxial testing conditions with simultaneous digital image correlation. Human temporal dura mater is mechanically highly variable with regards to its elastic modulus of 70 ± 44 MPa, tensile strength of 7 ± 4 MPa, and maximum strain of 11 ± 3 percent. Mechanical properties of the dura mater did not vary significantly between side nor sex and decreased with the age of the cadaver. Both elastic modulus and tensile strength appear to have constant mechanical parameters within the first 139 hours post mortem. The mechanical properties provided by this study can help to improve computational and physical human head models. These properties under quasi-static conditions do not require adjustments for side nor sex, whereas adjustments of tensile properties accompanied with normal aging may be of interest.

scholarly journals Study on the Effects of Perfume on the Mechanical and Colour Properties of Silk Fabrics

2017 ◽  
Vol 25 (0) ◽  
pp. 89-95
Author(s):  
Kavitha Krishnamoorthi ◽  
Srinivasan Jagannathan
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Abrasion Resistance ◽  
Cotton Fabrics ◽  
Colour Properties ◽  
Sensitive Skin ◽  
Dry Cleaning ◽  
Silk Fabrics

Perfumes are generally used to enhance the attitude of the person. Deodorants and perfumes are designed to be applied directly to the skin. Some people with sensitive skin may find that their skin does get irritated if they use too much perfume and hence apply perfume directly to their clothes. Silk is one of the most luxurious fabrics and is used on all occasions. If perfume is applied directly on fabric, it may cause a stain or discoloration and may spoil a costly garment. Although there is a study on the effect of perfume on cotton fabrics, there is no study about the effect of perfume on silk fabrics in the literature. Therefore this study aims to investigate the effects of perfume on dyed silk fabrics and is the first work on this subject. Mechanical properties like tensile strength, pilling and abrasion resistance were investigated, and the change in colour under washing, dry cleaning and perspiration were recorded.

Comparison of Textile Mechanical Properties of Cotton in Crosslinking with Dimethylolethyleneurea and Formaldehyde

1976 ◽  
Vol 46 (11) ◽  
pp. 813-817 ◽  
Author(s):  
U. Meyer ◽  
K. Müller ◽  
H. Zollinger
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Crosslinking Agent ◽  
Strength Loss ◽  
Cotton Fabrics ◽  
Degree Of Polymerization ◽  
Cure Process ◽  
Recovery Angle ◽  
Varied Concentration ◽  
Very High

Cotton fabrics were crosslinked with dimethylolethyleneurea (DMEU) and with formaldehyde by the pad-dry-cure process. The following parameters were varied: concentration of catalyst (MgCl2) and crosslinking agent, reaction time, and temperature. The crosslinked fabrics were characterized by dry and wet crease-recovery angles, tensile strength, and degree of polymerization. The results show that with DMEU a significantly better dry crease-recovery angle/tensile strength relation is obtainable. This difference is due entirely to a greater degradation of cellulose by hydrolysis in treatments with formaldehyde. Furthermore, in the case of DMEU the effect/strength loss relation can be improved by using very high resin concentrations in the padding liquor.

Comparison of Catalytic Activities and Textile Mechanical Properties Observed in the Crosslinking of Cotton with Highly Active Catalysts

1976 ◽  
Vol 46 (9) ◽  
pp. 691-697 ◽  
Author(s):  
U. Meyer ◽  
K. Müller ◽  
H. K. Rouette ◽  
H. Zollinger
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Catalytic Activity ◽  
Cotton Fabrics ◽  
Cure Process ◽  
Metal Chlorides ◽  
Catalytic Activities ◽  
Highly Active ◽  
Acids And Bases ◽  
Recovery Angle

Nine metal chlorides and mixtures of these salts with tartaric acid are compared with hydrochloric acid with regard to catalytic activity in crosslinking cotton fabrics with formaldehyde by the pad-dry-cure process. The sequence of catalytic activity can be rationalized by the hard/soft concept of acids and bases. When highly active catalysts are applied, the relation between dry crease-recovery angle and tensile strength is significantly improved for DMEU-cross-linked fabrics but only marginally improved when formaldehyde is used as the crosslinker.

Phase Transformations in Ti-7w/oMo-3w/oMe Alloy

1974 ◽  
Vol 32 ◽  
pp. 514-515
Author(s):  
S. Fujishiro
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Transmission Electron Microscopy ◽  
Tensile Strength ◽  
Mechanical Processing ◽  
Ray Method ◽  
X Ray ◽  
Transmission Electron ◽  
Water Quench ◽  
Alpha Beta

The mechanical properties of three titanium alloys (Ti-7Mo-3Al, Ti-7Mo- 3Cu and Ti-7Mo-3Ta) were evaluated as function of: 1) Solutionizing in the beta field and aging, 2) Thermal Mechanical Processing in the beta field and aging, 3) Solutionizing in the alpha + beta field and aging. The samples were isothermally aged in the temperature range 300° to 700*C for 4 to 24 hours, followed by a water quench. Transmission electron microscopy and X-ray method were used to identify the phase formed. All three alloys solutionized at 1050°C (beta field) transformed to martensitic alpha (alpha prime) upon being water quenched. Despite this heavily strained alpha prime, which is characterized by microtwins the tensile strength of the as-quenched alloys is relatively low and the elongation is as high as 30%.

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