• Title/Summary/Keyword: abrasion

Search Result 1,204, Processing Time 0.03 seconds

Surface Preparation and Activation Only by Abrasion and Its Effect on Adhesion Strength

  • Ali Gursel;Salih Yildiz
    • Journal of Adhesion and Interface
    • /
    • v.23 no.4
    • /
    • pp.101-107
    • /
    • 2022
  • Adhesive joints have many advantages such as weight savings, corrosion and fatigue resistance and now developed even withstand of high impact and dynamic loads. However, an adhesion has cumbersome and complicated surface preparation processes. The surface preparation step is critical in adhesive joint manufacturing in order to obtain the prescribed strength for adhesive joints. In this study, it was attempted to simplify and reduce the number of surface preparation steps, and abrasion and rapid adhesive application (ARAA) process is developed for an alternative solution. The abrasion processes are performed only for creating surface roughness in standard procedures (SP), although the abrasion processes cause surface activation itself. The results showed that there is no need the long procedures in laboratory or chemical agents for adhesion. After the abrasion process, the attracted and highly reactive fresh surface layer obtained, and its effect on bonding success is observed and analyzed in this research, in light of the essential physic and adhesion theories. Al 6061 aluminum adherends and epoxy-based adhesives were chosen for bonding processes, which is mostly used in light vehicle parts. The adherends were cleaned, treated and activated only with abrasion, and after the adhesive application the specimens were tested under quasi-static loading. The satisfied ARAA results were compared with that of the specimens fabricated by the standard procedure (SP) of adhesion processes of high impact loads.

A Study of Abrasion Rate of Coarse Aggregate (굵은 골재의 관한 연구)

  • Lee, Dong Young;Jun, Hyun Woo
    • Magazine of the Korean Society of Agricultural Engineers
    • /
    • v.12 no.3
    • /
    • pp.2013-2018
    • /
    • 1970
  • Abrasion rate of coarse aggregates is an important factor to determine aggregates quality. Allowable limit of abrasion rate of coarse aggregates for concrete is 40% according to K.S. Strength and durability test of concrete with 19 efferent aggregates were made. From this test, it was found that allowable limit of abrasion rate of aggregates can be increased to 43%.

  • PDF

A Study on Relationship between Point Load Strength Index and Abrasion Rate of Sediment Particle (퇴적물 입자의 점하중강도지수와 마식율의 관계에 대한 연구)

  • Kim, Jong-Yeon
    • Journal of the Korean Geographical Society
    • /
    • v.43 no.6
    • /
    • pp.808-823
    • /
    • 2008
  • Sediment abrasion in rivers is caused by the interaction between bedrock channel bed and sediment particles transported through the river. Abrasion rate of sediment particles in rivers is controlled by two major factors; Sediment transport conditions including hydraulic conditions form the erosive forces and physical and chemical strengths of the particles form a resistance force against abrasion and other erosional processes. Physical experiments were performed to find the role of each variable on sediment abrasion process. Total 266 sediment particles were used in this experiment. All sediment particles were divided into 11 independent sediment groups with sediment particle size and sediment loads. Each sediment groups were abraded in tumbling mill for up to 8 hours. Changes in weight were recorded by run and total: 2,128 cases of abrasion rate were recoded. Physical strength of rock particles was measured with point load strength index. It is found that sediment abrasion rate has a negative functional relationship point load strength index ($I_{a(50)}$) ($R^2=0.22$). It was suggested that physical strength of sediment particles set the "maximum possible abrasion rate'. As sediment flux increases, abrasion rates of sediment particles with similar point load strength index were changed. It could be concluded that not only physical characteristics of sediment particles, but also sediment transport conditions control sediment abrasion rates.

Correlation Between Factors Related to the Foot Shape and the Foot Abrasion in Wearing Ladies' Shoes (숙녀화 착용시 발의 형태요인과 장해부위와의 상관)

  • 김순분
    • Journal of the Korean Society of Costume
    • /
    • v.52 no.2
    • /
    • pp.71-80
    • /
    • 2002
  • The purpose of this study was to examine the correlation between the shape of the foot and foot abrasion. and to provide preliminary data for shoe manufacturing by comparing the length of a woman's feet and the shoe size. The Martin calibrator and measuring tapes were utilized to measure the shapes of 163 female college students' feet. Indirect measurements were also obtained by line drawing of the feet for additional analysis. Brief questionnaires about what type of shoes are worn were given to the subjects of the study. Data analysis was presented by frequency, percentage, and standard deviations. Factor analysis and correlation co-efficiency of data was conducted on the significance level of p〈.05. The results of the study are as follows (1) The average number of days per week in which the subjects wear ladies' shoes per week were 4.5. Little over half of the subjects (53.87% ) answered that they wear heeled shoes for more than 8 hours per day. The most preferred height of a ladies'shoe heel was between 2 cm and 4 cm, as replied by 41.0% of the subjects. (2) The foot area where abrasion occurs most often was around the heel (51.2%) and the middle part of the sole (50.9%) (3) Factors correlated to the heel abrasion included the circumference and the breadth of the foot. The abrasion on the side of the first toe of mid-sized feet was most affected by the angle of the first the and inner foot line. The height of the foot heel was a significant factor for the abrasion near the anklebone. In conclusion, the abrasion resulted from the inappropriate fitting of the shoe and the foot. Also, the circumference and the width factors were more influential rather than the foot length. Therefore, more database on this should be systemized and available to the footwear manufacturers and the customers for more practical use of shoe size and public education.

Analysis on the Cause of Abrasion according to Deformation Types of Seaside Armor Stones in Saemangeum Seadike (새만금방조제 해측피복석의 변형유형에 따른 마모원인분석)

  • Son, Jae Gwon;Goh, Nam Young;Choi, Jin Kyu;Kim, Hak Won
    • Journal of The Korean Society of Agricultural Engineers
    • /
    • v.55 no.6
    • /
    • pp.187-196
    • /
    • 2013
  • This study is focused on analyzing the deformation types of seaside armor stones based of field survey in order to establish the cause of abrasion following the deformation of seaside armor stones. 1. The deformation of seaside armor stone in saemangeum sea dike was classified as three different types: floating, deviation, and abrasion. 2. It was discovered that the stones floated to the extent of maximum 50 m, as the result of inspecting floating stones which were situated on different ten places. 3. The average number of deviation in the high ocean wave section was four times more than that in the ordinary ocean wave section, as a result of comparing the deviation number of the ordinary ocean wave section and that of the high ocean wave section for the purpose of inspecting the relation between the deviation of armor stones and the effects of ocean wave. 4. The angular shape of armor stones seen in the initial construction period has been abraded smoothly, as result of comparing of the shape change of armor stones for the purpose of inspecting abrasion state of seaside armor stones. 5. It was discovered that the abrasion of armor stone was severe in the section of many floating stones, as a result of analyzing the levels of abrasion and the cumulative sections of floating stones for the purpose of investigating the cause of abrasion.

Countermeasures to Irregulor Abrasion of Section Insulators for Electric Railroad Catenary (전차선 절연구분장치 절연재의 이상마모 대책)

  • 최규형
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.16 no.6
    • /
    • pp.87-94
    • /
    • 2002
  • As a section insulator dividing the electric railroad catenaries with different phases, the AC/DC section insulator which divides AC and DC railroad catenary have the complex structure, and suffer irregular abrasion on the surface or insulator rods when it is installed at the underground railroad. This paper intended as an investigation of the irregular abrasion of section insulators, provides the field measurements of abrasion level along insulator length and the abrasion patterns. The height variation of insulator parts and the balding length of insulators against pantograph's contact force are analysed experimentally, and the irregular abrasion mechanism is clarified with the help of theoretical analysis on the interaction between pantographs and section insulators. On the basis of experimental and theoretical analysis, the countermeasures to reduce the irregular abrasion are provided too.

Effect of Silica Fume and Slag on Compressive Strength and Abrasion Resistance of HVFA Concrete

  • Rashad, Alaa M.;Seleem, Hosam El-Din H.;Shaheen, Amr F.
    • International Journal of Concrete Structures and Materials
    • /
    • v.8 no.1
    • /
    • pp.69-81
    • /
    • 2014
  • In this study, portland cement (PC) has been partially replaced with a Class F fly ash (FA) at level of 70 % to produce high-volume FA (HVFA) concrete (F70). F70 was modified by replacing FA at levels of 10 and 20 % with silica fume (SF) and ground granulated blast-furnace slag (GGBS) and their equally combinations. All HVFA concrete types were compared to PC concrete. After curing for 7, 28, 90 and 180 days the specimens were tested in compression and abrasion. The various decomposition phases formed were identified using X-ray diffraction. The morphology of the formed hydrates was studied using scanning electron microscopy. The results indicated higher abrasion resistance of HVFA concrete blended with either SF or equally combinations of SF and GGBS, whilst lower abrasion resistance was noted in HVFA blended with GGBS.

MEMS Capacitive Gap Sensor for Measuring Abrasion Depth of Gun Barrel Rifling (포신 강선의 마모 깊이 측정을 위한 정전용량 방식의 MEMS 간극센서)

  • Lee, Seok-Chan;Lee, Seung-Seob;Lee, Chang-Hwa
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.33 no.9
    • /
    • pp.976-981
    • /
    • 2009
  • MEMS capacitive gap sensor is developed for measuring abrasion depth of gun barrel rifling. Measuring abrasion depth of gun barrel rifling is very important because it is related with exactness of firing and life of arms. The method using a gap sensor is not to hurt rifling. And it can measure abrasion depth through minimum shooting, because the developed gap sensor can measure from $1{\mu}m{\sim}12{\mu}m$ using Polydimethylsiloxane(PDMS) material and making a stretchable electrode on PDMS. And it's resolution is 1 ${\mu}m$ using capacitive method and MEMS technology.

Changes on the Abrasion and Mechanical Properties of Warp Knitted Fabric for Footwear with Softeners and Heat Treatments (유연제 및 열처리에 따른 신발용 경편성물의 마모 및 역학 특성 변화)

  • Jeon, Youn-Hee;Koo, Ja-Gil;Jeong, Won-Young;An, Seung-Kook
    • Fashion & Textile Research Journal
    • /
    • v.12 no.4
    • /
    • pp.494-499
    • /
    • 2010
  • Knitted fabrics are very popular for their numerous advantages such as greater comfort, attractive garment appearance, better fit on the body, etc. In this study, we investigated the mechanical properties and abrasion property of warp knitted fabrics for footwear which treated with several softeners to improve abrasion resistance. The antistatic softener among the various softeners showed high improvement in abrasion resistance. Among the mechanical properties with treating conditions, WT (tensile energy), G (shear stiffness), B (bending rigidity) increased as treating timeincreased. But the other mechanical properties were little changed with treating concentration.

Improvement of Abrasion Resistance and Friction of Rubber Blend Composition

  • Lee, Jong-Hwan;Lee, Jieun;Han, Tak Jin;Jeong, Hye Min
    • Elastomers and Composites
    • /
    • v.55 no.3
    • /
    • pp.161-166
    • /
    • 2020
  • On the basis of the use of shoes, the outsole, which is mainly made of rubber, has various characteristics. The most important of these characteristics is abrasion resistance and friction. Generally, the abrasion resistance can be improved by adding more reinforcing filler such as silica to the rubber; however, the friction force drops. Owing to these problems, rubber having excellent abrasion resistance and rubber having excellent frictional force are blended. In this study, various characteristics, including wear resistance and friction, were evaluated by blending NBR/SBR or NBR/BR mixture with high wear resistance and CIIR with high friction. The CIIR was increased up to 60 phr, whereas the friction wear characteristics were rapidly changed in the NBR/CIIR blend ratio from 75:15 to 60:30.