Curling movement trajectory influence factor dynamic analysis and counter measurements

Size: px

Start display at page:

Download "Curling movement trajectory influence factor dynamic analysis and counter measurements"

Arleen Franklin
5 years ago
Views:

1 Available online Journal o Chemical and Pharmaceuical Research, 2014, 6(3): Research Aricle ISSN : CODEN(USA) : JCPRC5 Curling movemen rajecory inluence acor dynamic analysis and couner measuremens Fei Dong Deparmen o Basic Courses, Henan Mechanical and Elecrical Engineering College, Xinxiang, China ABSTRACT Curling has been rapidly developed in he srong suppor o naion, and i gradually becomes a kind o newly-developed ho po even. Though China curling ges rapidly developmen in a shor ime, i sill aces some pracical problems in developing. This paper applies biomechanics knowledge ino analyzing curling inluence acors. Considering ahlees delivery moion, ice wiping echnique as well as eam work aecs he compeiion. By research, i designs simple program low char wih indicaor lamp licker requency o guide ahlee raining, in he hope ha plays posiive roles in assising curling beginners and guiding ahlees raining as well as oher aspecs. Key words: biomechanics, delivery moion, ice wiping echnique, momenum conservaion INTRODUCTION Wih he developmen o social and he improvemen o living sandards, curling has gradually come ino ordinary people s vision. In 2010, our counry women curling eam reached new heighs in ancouver Olympic Winer Games, hey became world op eam, and curling became more and more popular. However, curling mass oundaion in our counry is poorer; hereore scieniic raining is especially imporan o China curling developmen. While domesic curren raining mainly relies on experience o do raining, i obviously doesn work, so i is imperaive o carry ou scieniic analysis o curling [1-3]. Curling po body is a relaive regular ampulla s, is sliding, aing, colliding in ice surace all can be regarded as rigid aion ypical examples [4, 5]. In curling running process, ahlees give i aion, curling and rough ice surace ricion orce; wiping moion changed ice surace ricion orce and so on all are o grea imporance o curling movemen rajecory. In curling movemen process, i no only has orward laion, bu also accompanies wih some aions, which causes curling making displacemen in he laeral o orward direcion, is moion rajecory is in arc no line [6-8]. The essence o curling runs in he ice surace is cylindrical rigid body mass cener laion and aion around mass cener. In pracical delivery applicaion, experienced delivery ahlees can give curling clockwise or aniclockwise angular speed and dieren linear iniial speed wih dieren acics, so as le curling arrive a expeced moion rajecory [9]. Scholar Denny.M in aricle Curling rock dynamics, by experimen research comparaive analysis, i ound some orces ha aeced curling displacemen delecion in movemen process, and divided hem ino le-righ asymmeric orces and ore-aer asymmeric orces. While Mark R.A. Shegelski and oher scholars by experimen veriying o le-righ asymmeric orce and ore-aer asymmeric orce, hey ound curling horizonal delecion movemen mainly was aeced by ore-aer asymmeric orce no le-righ asymmeric orce, he research resuls unil now is sill widely discussed bu by ar is relaive universally acceped saemen [10]. Thereore, deine arge as research curling movemen disance inluence acor, esablish more raional physics model, and sudy ice wiping inluences on curling rajecory hese hree aspecs problems. Among hem, i mainly uilizes some physics and mahemaics knowledge o esablish raional models, meanwhile carries ou correlaion 346

2 analysis hrough nework searching los o curling daa. CURLING MOEMENT TRAJECTORY INFLUENCE FACTOR MECHANICS ANALYSIS This paper akes aniclockwise aed curling as research arge, makes analysis o curling movemen rajecory. Symbols explanaion m Curling mass Uni: g v Curling insananeous speed when i leaves rom ahlees hand( iniial speed) Uni: m/s u Ice surace dynamic ricion coeicien g Graviy acceleraed speed Uni: m 2 /s S Curling oal disance rom leaving ahlee hands o ending Uni: m a Curling average acceleraed speed Uni: m 2 /s Curling dynamics analysis Curling cour ice surace is composed o los o cobble like dewiness small paricles ha no smooh; he boom o curling is a crooked and hollow concave plane, is conac surace wih ice surace is a ring shape hin surace wih diameer o 12.5cm, widh only 3-5mm. On he condiion ha no ariicial acors change ice surace ricion coeicien, curling in proceeding process, aeced by ineria, curling graviy cener moves orward, he irs hal par o circular ring conac surace pressure acing on he ice surace is larger han he second hal par pressure acing on he ice surace, posiive pressure acing on he ice surace caused skin layer ice surace insananeous meling, hereore curling boom conac ring irs hal par ricion orce is smaller han he second par one, aeced by ice surace unevenness, cour inside and ouside emperaure dierences as well as curling suered dieren aion and push orce when ahlee hrows i ou o hands hese mule acors, skin layer ice surace will accelerae meling, ice surace and curling conac surace orm ino a layer o quie hin liquid ilm. The ilm beween curling and ice surace will generae an adhesive orce; driven by curling aion, he ilm will ae ogeher wih curling, i will orm a drag orce opposie o aional direcion in he surrounding o conac surace ha le curling irs hal par ricion orce become more small, so ha or he mos par, we can observe ha in pracical delivery process, aniclockwise aing curling aer a momen sliding, is movemen rajecory will gradually appear an obvious le shiing. As Figure 1 show: Figure 1: Aniclockwise aing curling In Figure 1, he doed arrows respecively represen curling irs hal par conac surace and he second hal par conac surace movemen direcions, solid arrow represens curling irs hal par conac surace suered ricion ron orce and second hal par conac surace suered ricion orce back, due o back larger han, curling will appear leward shiing phenomenon. Similarly, clockwise aing curling movemen rajecory will gradually show an obvious righward shiing aer sliding or a momen. In whole movemen process, curling is divided ino linear movemen and aion wo pars, so in exploring curling movemen rajecory change process, we will respecively discuss dieren aional linear speed and hrough mass cener laional speed( in he paper jus call sraigh-line speed or shor) inluences on shiing phenomenon. By esablishing recangular plane coordinae sysem, i analyzes dieren siuaions sraigh-line speed and linear speed inluences on curling delecion. A irs, esablish a round plane wih curling sliding radius as radius, sliding radius is curling conac surace circular ring ouside and curling mass cener projecion in round plane connecing line. Esablish y axis in round plane wih hrough curling mass cener insananeous linear speed direcion, in plane y axis verical direcion o esablish x axis. From his, we can divide round plane ino 4 quadrans, and selec one o hem o make ypical analysis, assume curling along aniclockwise direcion aion concree speed direcion as Figure 2 shows: ron 347

3 Figure 2: Curling aing along aniclockwise saus analysis In Figure 2-a, random selec curling conac ring poin A, ωis curling angular speed, θis x axis along y axis direcion one included angle when curling aes, rom which 0 θ π/2.the direcion o y axis is he direcion pass curling mass cener linear insananeous speed aing insananeous linear speed( =r ω), join speed can use s o express, hen i has:, esablish x axis in he verical y axis. is curling is insananeous linear speed hrough mass cener, heir s= + (1) and, s all are curling speeds in solid ice surace, and s posiions in x axis relaed Among hem, θangle. In Figure 2-b, speed along angen line and speed along radius direcion x orm ino join orce s, ha is: s = x + (2) In Figure 2-c, we already knew poin A one ix ice surace speed s, aion linear speed and linear speed. Due o curling passes hrough liquid ilms, a ha momen, i aes quickes wih curling conneced upper surace, lower layer liquid ilm ha close o ice surace will no ae wih curling bu drawn o curling circular ring conac surace main angen lines surrounding wihou being verical o conac surace, and r are speeds organized by solid ice surace along posiive angen direcion and radius direcion, join speed, hen i has: is liqueying ilm r (3) Among hem, εis a correlaed angular coeicien( 0<ε<1), and s are no in he same direcion, i exiss a included angle, and curling in liquid ilm ice surace sliding speed is smaller han curling in solid ice surace sliding speed s, hen i has: = s (4) 348

4 In Figure2-c, doed line indicaion par is parallelogram, ΔF direcion and speed s are no in one line, ΔF is direcion opposie one acing orce ha is curling in liquid ilm ice surace aional sliding generaed ricion orce. εis a correlaed angular coeicien, i exiss in he range 0<ε<1, by consuling relaive oreign documens, i inds ou ha εvalue can be divided ino 3 inervals, ε 0;0<ε<1;ε 1.Is ime correlaed curling aional linear speed duraion and curling line sliding speed duraion raio / is posiive correlaed oεvalue. Then we can useεvalue variable o discuss /, while / raio is posiive correlaed o / raio, rom which we can useεvalue variable o discuss / raio, urher explore and discuss dieren and inluences on curling. 0, hen S along radius direcion componen speed r Whenε 0, will also ininie ge close o 0, a his ime i will have no orque o slow down curling aion, Mass cener speed opposie join orce sill exiss; According o energy conservaion, curling moion rajecory shows a gradually slowing line rajecory. Curling running in laional direcion is a gradually slowing movemen ill ends in expeced end poin. When 0<ε<1, conac ring poin A exiss one direcion opposie join orceδf. A his ime, i is no on he conrary wih S direcion, In curling aion process, due o ron ice surace pressure increases caused ice surace meling, makes ron ricion orce become smaller and smaller, curling orque will also become smaller and smaller, orce aecs curling aion will also become smaller and smaller, hen a his ime, curling aion will las longer han linear movemen ha is >, while > he poin ha we can obvious observe in pracical curling, while due o curling aion generaed laeral displacemen, especial in he inal movemen, we can see ha curling movemen rajecory has an obvious leward delecion., while a his ime S, curling sliding process ice surace doesn mel or jus Whenε 1, = only a lile meling ha is aion is very slow; a his ime acing orce on conac surace is on he conrary wih ice surace orce direcion, i will has no change on orque; hereore whenε 1, hen i has, Curling aion and linear movemen will almos simulaneously sop; Curling movemen rajecory will ge close o a line. Curling mass cener lies in geomeric cener ha is po cener, according o mechanics heorem o cenroid movemen, when curling suered orce hrough po cener, i orms ino laion, he laion conorms o P impulse heorem, and is impulse value is equal o momenum variable. I curling suered momenum Fd momenum variable: K m hen i has: F m (5) Among hem, P is he impulse ha curling suered when ahlee pushes ou i, F is curling suered orce, is orce acing ime, m is curling mass, is curling running process speed variable. Is laion kineic energy ormula is: he E m 2 2 (6) Among hem, E is laional kineic energy, m is curling mass, is curling running linear speed. Due o curling cour ice surace has los o dieren sizes and cerain heighs dewiness small puberance; o achieve acics requess, when ahlee makes delivery ou o hand, i oen inernal aes or ouside aes handle, le curling ae 2 o 3 weeks. In case ignoring ice surace ricion orce change siuaion, due o suered eccenric orce( no pass po cener orce) inluence, po body has laion and urning, curling acually makes orward verical aional laion movemen. As Figure 3 shows: 349

5 Figure 3: Curling movemen process When only discuss curling movemen rom leaving ahlee hands o saic such phase, and assume curling suered ricion orce sizes and direcion don change. Ahlee pushes ou curling rom saring poin, le i sop in ice unnel erminal numerous concenric circles, and ries o crash opponen po ou. Le s see curling movemen process. The hrower pushes curing, hey akes accelerae movemens ogeher (he process no be analyzed), curling hereore ges iniial speed. When hrower les i go, curling due o suered ice surace ricion, emporarily assume i makes consan deceleraed linear movemen, ill speed arrives a O. CONCLUSION By research, i is clear ha curling movemen disance is in direc proporion o iniial speed square while has no connecion wih curling mass. Disance rom service poin o arge cener is around 29.6m, hen combining wih ice surace pracical dynamic ricion coeicien, i can calculae roughly iniial speed when delivery. Bu unchangeable ricion orce and consan sraigh-line movemen are jus ideal sae saus, in ac due o irs base deviaion; second base ahlee is required o amend curling movemen rajecory and disance by wiping ice. Wiping ice is o increase ice inernal energy by overcoming ricion orce work, le ice surace mel wih a layer o hin waer so as o reduce ricion coeicien, in his way, curling can move orward urher and sraigh. In dry surace, when sphere moves, ron suered ricion orce is larger han he back one, and is aional direcion and sliding direcion are dieren. While he saus is jus on he conrary in liquid ice surace, because liquid layer reduces ron ricion, sphere sliding and aional direcion are he same. When member wipes ice, wo ahlees use brush wiping curling ice surace in ron o hem, le liquid ilm become more smoohly o conrol crooked exen and sliding disance when curling proceeds. American group implemened es shows he ice wiper can le curling walk around 4.8m arher. Curling rack versal surace is in he shape o U no horizonal, reason or such design is no ice maker aul bu relecion o ice maker proessional level. Because U shape ice surace can help high level ahlees play loop. Ice unnel surace is also no smoohly hereore dieren par ricions will be dieren when aing, aional speed and laional speed are dieren, hen coordinaes wih ice wiping, so i can play loop. In shor, i can change direcion, wipe curling in one side and anoher side no ha can cause curling wiped side ricion orce small and he oher side ricion orce big, so ha changes direcion. REFERENCES [1] TAN Wei-dong, LI Xue-qin, WANG Bing-yu. China Winer Spors, 2007, 29(3), 35-39, 42. [2] WANG Ke, FENG Wei. Journal o Shandong Physical Educaion Insiue, 2010, 26(4). [3] Feng Wei, Yu Tong, Niu Rongli. China Winer Spors, 2004, (1), [4] Yuan Lin, Yao Jun. Journal o Jilin Insiue o Physical Educaion, 2009, 25(3), [5] HONG Mei-ling. Bullein o Spor Science & Technology, 2011, 19(12), [6] LI Shu-qing. Bullein o Spor Science & Technology, 2011, 19(4), [7] Che Yi. China Winer Spors, 2002, (2), [8] XIAO Guo-dong. Journal o Hubei Spors Science, 2004, 23(2), [9] ZHU Zhi-qiang, SU He, WANG Yu-eng, MU Liang. China Winer Spors, 2011, 33(5), [10] Zhang B.; Zhang S.; Lu G.. Journal o Chemical and Pharmaceuical Research, 2013, 5(9),

Why Mendel Succeeded. Why Mendel Succeeded. Mendel chose his subject carefully. Mendel chose his subject carefully. Mendel chose his subject carefully

Why Mendel Succeeded. Why Mendel Succeeded. Mendel chose his subject carefully. Mendel chose his subject carefully. Mendel chose his subject carefully Why Mendel Succeeded I was no unil he mid-nineeenh cenury ha Gregor Mendel, an Ausrian monk, carried ou imporan sudies of herediy he passing on of characerisics from parens o offspring. Characerisics ha