alo semua...
nie aku nak share sket info Composite Materials (CM)...
korang minat x bidang CMs?
amende? composite materials? aku tak tau lah, stok composite kat bursa saham kuala lumpur aku tau larr
bg yg tatau amende CM nie...CM is anything that has fiber reinforcement strands plus resin matrix...kadang2 definition dier includes coring (as if core) materials mcm plywood, foam core atau aluminium honeycomb structure..
so ikut definition composite materials = fiber reinforcement + resin matrix + coring materials
structure composite materials, laminate schedule
generally, structure composite materials nie is made up by these three components....fiber, matrix ngan coring materials...
this kinda structure kita panggil sandwich construction...pasal bentuk dier macam sandwich...which is illustrated in the pictures below
top outer skin - fiber reinforcement (4 - 3)
middle structure - coring material (2)
resin matrix- tak nampak coz nie matrix dier, macam filler or binder
contoh coring material, honeycomb structure
nie contoh sandwich composite...literally mcm sandwich cuma beza dier sandwich composite nie keras gaban n takde rasa, kecuali rasa minyak sket la...nak gigit boleh, but kene pakai gigi emas la, gigi buatan kalsium mmg akan patah
back to topic, kadang2 ade structure tue tak pakai coring material, instead derang pakai solid composite structure...meaning, only using fiber reinforcement plus resin matrix je...camnie pon orait gak, but amount of resin biasanya akan tebal sket selain specific strength fiber tue kene power macam carbon, aramid (commercially known as KEVLAR) or E-glass (fiberglass arrr)
coring materials lak only added klu derang nak increase strength to weight ratio, pasal coring materials nie porous (lubang2) so ringan sket...macam balsa end grain wood, BALTEK, foam cores mcm Core-Cell and DivinyCell
materials
materials utk composites nie lak ade 3 jenis, macam aku cakap tadi..which are fiber reinforcement, coring ngan resin...
ill start with fiber reinforcement
fiber nie ade 2 jenis, natural ngan synthetic...yg natural mcm cellulose, wood fiber, cotton, hemp, jut or dietry fiber..nie sume natural, and sume nie x sepower synthetic nye fiber coz application lain2...
synthetic fibers lak yg mcm biasa kita dengar E-glass, Carbon (graphite), Aramid (used for KEVLAR, Nomex, Technora & Twaron), Nylon, Rayon ngan Acrylic...dlm byk2 nie masing2 ade pros and cons sendiri...contoh, e-glass or fiberglass murah utk manufacture but dier nye compressive (tekanan) or sheer (tegangan) strength tak sekuat carbon coz dier made up of silica (macam kaca) so brittle (rapuh)...carbon lak mmg otai, but mahal gaban...utk kete F-1 bole arrr carbon fiber nie...klu utk boat mancing lak, e-glass is recommended
carbon fiber mat
comparison between carbon fiber ngan rambut manusia...carbon fiber hitam & kecik, rambut manusia lak yg besa kaler terang tue
fiberglass roving...halusss jek, korang wat rambut rebonding pun x lurus camnie hahahaha
k move on to coring materials..mcm aku cakap tadi, ade macam2 jenis coring materials, nak pakai plywood bole gak (utk marine application ade Meranti BS1088 klu x silap aku), foam core mcm Core-Cell, DivinyCell, Honeycomb aluminium, Balsawood, or BALTEK...sume nie antara coring materials yg common org pakai utk composite materials...lightweight n superstrong bile combine ngan fiber skin n resin...lembut gak easily molded to any shape, but tak selembut jari jemari ompuan ar...phewwiitt
utk resin lak...ade a few types juga..macam polyvinyl ester resin, polyester resin or epoxy resin...epoxy resin ngan polyvinyl ester resin paling famous ar...kenape famous? next part aku citer lak manufacturing modes
manufacturing modes
byk cara utk manufacture composite materials nie...the earliest method of composite materials manufacturing method in modern human history dated back to 1939...but big scale production didnt start until late 1950s...coz masa nie raw materials utk vehicle & vessel parts x mencukupi (read, metal, aluminium n besi) due to previously fought WW2...so manufacturers like DuPont & the geng ventured into composite materials la around this period....
so paling basic skali is Hand Lay Up technique...cara nie senang but kotor n wasting a lot of materials....cara nya camnie, a cloth of fiber material is laid up on molding surface....molding surface tue terlebih dahulu kene sray ngan gel coat (kaler/coating/paint---basically resin with pigments) ngan disengagement agent (so senang ko nak kuarkan parts tue dr mold bile composite dah keras)....lepas ko lay up fiber material, then ko sapu resin ngan roller atas fiber material tadi...macam mengecat la...nie susah sket coz hand lay up technique nie dier nye strength mmg differ from point to point..meaning, depending ngan orang yg wat tue...kadang2 surface tue tak uniform...hence kene lay up byk layer fiber material....lepas siap, kene biar a few hours (depending ngan jenis resin yg ko pakai) so that resin tue kering n fully meresap dlm fiber material n mengeras...derang panggil nie 'curing'....
hand lay up diagram
lagi hand lay up
technique no 2, yg paling senang ialah sray up....technique nie biasa akan pakai CSM (chopped strand mat) nye fiber material yg akan masuk dlm chopper gun, in which it is mixed with resin before being injected/sprayed at high velocity on the mold surface....so fiber tadi kene chop dlm gun tue...then campur ngan resin before kene tembak kat surface mold...cara nie mmg x uniform in terms of surface strength, so layer nie kene tebal....teknik nie paling salu org Msia pakai utk wat boat...again, mold tue kene sray dulu ngan gel coat or disengagement coating (aku lupa la nama khas bahan nie...huhuhu)
so btw, salu nya derang akan taruk coring material lepas derang wat 2 teknik di atas...so after a few layers of fiber material n resin, taruk coring material, then apply again few layers of fiber material plus resin...so that it'll become sandwich...
-------------------------------------------------
sampai nie dulu arrr aku tulis..penat, nak dinner dulu...tadi baru je lepas tangkap ikan koi kat kolam...
teknik yg aku akan explen sket2 pasnie ialah
---vacuum resin infusion
---resin transfer molding
---pultrusion molding
antara benda yg korang leh buat pakai composite materials nie is as below:
boats
hull nie klu x silap derang wat pakai coring material utk framing plus solid composite hull kat bawah
bila dah siap camnie ar rupa boat tue...tahan lasak
buat sportfisher (sportfishing boat) pakai fiberglass...sandwich construction ngan marine grade plywood
nampak x fiberglass cloth? lembut yerrr...bile dah keras, lagi tajam dari pisau...klu kene musti berdarah nyer
rolling adhesive/filler agent kat fiberglass surface
hull yg dah di'glass'kan
hull fishing boat yg akan kene glassed...
close view hull...atas tue glass cloth..tak kene resin lagi
nie dier KEVLAR..klu korang main CS maybe korang tau la menatang nie...bahan nie aramid fiber...
yg wat dier kalis peluru sbb dier nye structure ngan fiber tue leh absorb impact and spread it within the matrix...tue yg special pasal aramid fiber nie...thats why dier paling sesuai utk kalis peluru nye application...
car parts yg derang wat pakai composite...yg nie lak simple fiber plus resin..sometimes derang letak coring material yg easily shaped mcm Core-Cell & the gang...
carbon fiber bumper plate...nampak weaving fiber cloth tue...tebal n superstrong n super mahal....
carbon fiber spoiler
bulletproof police shield...derang wat dr polycarbonate...polycarbonate nie reinforcement dier...kadang2 campur ngan polyeurethane sebagai matrix...but dier nye construction more to ply rather than fiber strands...so lenkali klu nak wat rusuhan, jgn pakai botol kaca coz polis xkan sakit...korang pakai la armor piercing bullet..hahahaha
this is indeed a good thread. Should have given you lots of credits.
- kalau asbestos tu cam ner pulak ? adakah ia composite?
- kenapa manusia fascinated sangat dengan RESIN?
- actually bidang ni apa skop dia?
- u need to analyse materials at which level ? atomic ? sub atomic ? to what extent? aim? the "holy grail" dalam bidang ni apa ek?
ambil contoh The Airbus kan? berapa banyak tan composite materials yg depa guna?
- then lastly those ceramics? would this be the type of " materials" studied by the field too?
and how about the use of this materials across field/ discipline - like i dunno, like medicine etc? or anything jer lah .. kalau aerospeace mmg sangatlah kan?
salah satu bidang aeronautics la kan,
selain tu aerodynamics in F1 car la
nakkan material yg tahan, kuat dan reliable,
easy to handle, dan paling penting ringan,
pernah tgk model UAV menggunakan fiberglass as body dia,
wing, and body made of fiberglass,
produce dlm lab je,
ceramics, ada kegunaan dlm bidang high voltage engineering,
tp skang ni byk dah migrate ke polymeric technlogy,
use as main insulators / non conductive materials
asbestos is a composite...asbestos itself is a naturally occuring fiber...kalau utk insulation macam atap rumah, asbestos tue dah dicampur ngan simen or filler plaster sebagai matrix...bahaya kalau asbestos nie pecah coz fiber dier halus2...masuk badan leh kene cancer
resin? ntah la naper fascinated...but one of the reason maybe kat dier nye application yg widespread...natural resin mcm damar org salu pakai utk tampal lubang perahu..synthetic mcm epoxy or polyester org salu pakai utk adhesives (gam kuat), or coating (paint..taruk pigment or colorant) or insulator ...difference dier ialah additives ape derang letak, mcm flame retardant ke, plasticizer ke etc
skop composite material nie cross-field antara mechanical-chemical-materials engineering...mechanical lak deals ngan calculation of strength pakai matrix (matrices), chemical mostly deal ngan processing ngan molding techniques, while materials literally deals with materials themselves mcm tensile strength, stress, youngs modulus etc...
composite materials nie xyah analyse sampai sub atomic level because u can easily analyse its strength if u know the laminate schedule (susunan fiber material in relation to each other dalam sandwich structure tue)....
contoh, basic laminate schedule biasa nya 0/45/90/-45/0....which means sandwich tue ade 5 fiber skin on top of each other....paling bawah skali being 0 degree horizontal to your eyes, followed by fiber cloth (yg mana lining fiber dier) 45 degree to the first one...then followed by 90 (at right angle or vertical) to your eyes...so on n so forth..so based on laminate schedule n matrix type camnie, derang leh analyse strength tue in all direction pakai matrix system...
thats why derang ske pakai composite coz u can tailor the material strength to ur needs in any direction u want...duit je jadi penghalang..hehehe
airbus lak aku tatau baper tonne...but kalau x silap last few years lecturer aku bitau, dalam 40-60 % composite...maybe im wrong kat sini, so hopefully sapa yg tau leh share sket info airbus nie...
ceramics yes ...one of those ancient traditional composite...lama dah ceramic nie,dated back to 4th or 5th century...but org dulu pakai utk wat foundry mcm blacksmith coz ceramic nie tahan gile utk high temperature application...but in terms of compressive strength, ceramics klu x silap, x setahan modern age composite mcm e-glass, carbon etc etc...so not much focus kat ceramic unless if u r dealing with metal smelting nye industry coz ceramic derang pakai utk jadik mangkuk utk simpan molten metal...
medicine? dah ada dah derang pakai...but more to ceramic type, utk wat prosthetic tulang sendi, joint kat buku kaki etc etc...but this one is tricky la coz utk joint kat sendi tue, composite type tue kene tahan abrasive condition and kene tahan corrosive fluid dlm badan (just in case)..aku agak2, utk tulang betis pon ble gak..hehehe...senang lari pecut, nnti kalah watson nyambek
a ah, manufacturing utk aeronautics, aerospace, F1 tue toksah cakap...mmg banyak composite kat situ esp carbonfiber..
aerospace, heat insulation kat bawah space shuttle tue ceramics...klu x silap asbestos
composite nie mmg otai lah...kalau compare weight to strength ratio composite ngan metal or alloy....composites lead miles ahead of the conventional metal, and almost at par ngan super alloys with cheaper costs
but one of the drawbacks kat composite nie, dier susah nak recycle...coz dier nye substance tue fiber lining plus resin matrix...bile dah sebati, dua2 mende nie mmg susah nak disintegrate...but few years back DuPont in conjuction with Toyota, dah buat teknik utk recycle composite...40-70% success rate la depending ngan types of fiber ngan matrix dier...Toyota supply parts utk recycle, DuPont research the process....
mostly kelebihan carbon based?
-sbb compressive strength dier lagi kuat...and lagi ringan..this gives dier nye strength to weight ratio lagi tinggi...mostly at a cheaper manufacturing cost than using modern superalloys mcm titanium, tungsten, molybdenum & chromium variants..tp dlm composite materials...carbon based composite antara yg mahal la...but definitely cheaper than using modern super alloys
-readily available yes u can say it that way....klu u nak, u leh wat any composite parts even kat belakang umah sendiri....cuma space je jd limitation as to what extent the size will be.....bole wat in any combination u want depending ngan application...even carbon fiber pun available dlm different configuration anyaman mcm weaving, chopped strand mat, roving...so u senang tau which one nak pakai...
-in general, manufacturing nie paling lama pun dlm masa sejam...meaning masa utk ko start mix resin ngan fiber cloth...therefore, byk composite parts yg ko leh buat dlm masa sehari depending ngan berapa byk workforce n space u got there...provided that u already have a mold in place...mostly mold dier pun simple, kadang2 pakai cold molded, but kalau nak senang, buat cara biasa la, pakai female mold yg buat dr full scale male plug (full scale part)
-durable mmg durable, mostly at par ngan alloys...cuma beza dier, composite materials nie takde melting temperature, takkan yielding at different temperature (sbb most resins derang pakai are thermosets)....xde masalah too much regarding thermal or moisture buckling mcm kayu or alloy (yielding)...let say application ko tue involve bentuk mcm curve...then u tailor it so that its original shape is curve...xyah nak wat steam bending mcm kayu...
-modern manufacturing techniques mcm vacuum resin infusion makes it almost dirt-free and zero volatile emission to make any composite parts....plus teknik nie la paling effective and it gives the optimum fiber to resin ratio for maximum weight to strength ratio...which means ko leh manufacture composite parts pakai sluar pendek ke, pakai baju opis ke...xkan kotor nye...plus reduce wastes as compared to traditional methods...
-one of the best feature pasal composite nie because of its resin...resin kan macam glue/adhesives...and even used for coating or paiting...which is basically resin with pigments...this makes it even better sbb bonding between coating layer ngan main parts mmg kuat becoz they r bonded chemically aside from being the same material (resin-resin)..so u can expect coating (painting) dier tahan lama banding ngan metal surface, in which ko kene pakai electron deposition (mahal) klu ko nak dpt coating yg tahan lama...
in the process of producing these composites, would u consider them as environmentally -friendly?
2) Certain countries that are known to be an earth quake -prone, like Japan etc...surely would be thinking twice of constructing new structures etc in their cities, and my question is:
- would a country geographical profile be one of the factors considered in choosing any composite material?
regarding ur question, geographical profile is definitely one of the factors tht determines materials for construction..sbb some composites will behave differently than others in terms of moisture absorption, tensile strength, sheer strength & available weaving n laminate schedules....but derang xkan pakai the same material for the whole structure...macam derang wat aircraft airbus tue...definitely derang akan pakai mix n match nye combination...let say, basic framing would be using conventional steel n rebar combination and other composite materials for internal structures....steel rebar in cement/concrete nie pon ko leh anggap sbagai composite cuz dier pakai rebar as 'fiber reinforcement' plus cement or concrete as matrix...cuma definition dier je tak berapa fit utk modern composite because utk modern composite, fiber definition would be anything that has almost infinity length to diameter ratio (L/D)...coz biasa kita tengok rebar nie mostly pendek2..
anyway, utk building, i believe internal structure mmg byk yg ble wat dr composite...klu x silap in the late 50s, royal british navy kot, ade wat submarine pakai composite....because unlike metal, composite nie more like sound proof n absorption...so almost undetectable by sonar/radar during that era...im sure with the current technology n materials available at disposal, better quality can be applied to building large structures mcm bangunan...so i hope that answers ur doubt (if any) regarding the strength capability of composite materials...
bangunan composite JP Morgan Chase
JPMorgan Chase Tower is the tallest composite building in the world. The office tower is clad in pale gray polished granite, stainless steel, and gray glass. The western corner of the tower has been sheared off to form a five-sided structure. The western facet of the tower is formed by an 85 foot wide free span of glass that ascends the full height of the building.
The tower is positioned on a one-acre plaza to create a large public space. The area is embellished with patterned granite paving, extensive landscaping, including a water garden and Bradford Pear trees, and a major sculpture. This area serves as an important open space for downtown Houston. JPMorgan Chase Tower rests on a full city block in the northwest quadrant of the downtown area, bounded by Capitol, Texas, Travis and Milam Streets. JPMorgan Chase Center, a twenty-story facility housing a parking garage, healthclub and data processing center, is located adjacent to the Tower, across Travis Street.
nie sket info yg aku pakai masa wat research utk ada satu paper composite suatu ketika dahulu...
Why Composites?
Composites are able to meet diverse design requirements with significant weight savings as well as high strength-to-weight ratio as compared to conventional materials. Some advantages of composite materials over conventional one are mentioned below :
-Tensile strength of composites is four to six times greater than that of steel or aluminium.
-Improved torsional stiffness and impact properties
-Higher fatigue endurance limit (up to 60% of the ultimate tensile strength). --fatigue strength nie mcm cyclic load...byk materials esp metals kalau dah lama sgt under until fatigue limit, salu nye akan yielding...mcm ko bengkokkan keping besi, last2 koyak...
-30-45% lighter than aluminium structures designed to the same functional requirements
-Lower embedded energy compared to other structural materials like steel, aluminium etc. (tak energy intensive mcm aluminium n steel smelting)
-Composites are less noisy while in operation and provide lower vibration transmission than metals (definitely an advantage utk submarines)
-Composites are more versatile than metals and can be tailored to meet performance needs and complex design requirements
-Long life offers excellent fatigue, impact, environmental resistance and reduced maintenance
-Composites enjoy reduced life cycle cost compared to metals
-Composites exhibit excellent corrosion resistance and fire retardancy
-Improved appearance with smooth surfaces and readily incorporable integral decorative melamine are other characteristics of composites
-Composite parts can eliminate joints/fasteners, providing part simplification and integrated design compared to conventional metallic parts
hari nie haku nak sambung balik info2 pasal composite materials nie lak...
this time haku akan briefly explen 3 lagi manufacturing methods yakni
-vacuum resin infusion
-pultrusion
-resin transfer molding
start ngan Vacuum Resin Infusion
nie la teknik paling banyak org pakai nowadays but paling susah nak master sbb preparation steps dier mmg kene detailed...otherwise nnti parts tak menjadik or rosak...pakai teknik nie, advantage dier is less dirty, unlimited setting time ngan almost zero volatile emission...so korang x payah nak pakai gas mask masa nak wat composite...cost utk teknik nie lak haku agak2 dlm kategori medium expensive depending ngan brapa banyak equipment korang pakai...
(btw, teknik2 lain yg involve open air molding ngan composite materials mmg kene pakai mask coz thats the requirement/standards)..kalau korang tanak pun bole but accumulated effect dier mmg bahaya pasal resin nie polymers aka oil products...
basically antara equipment yg kene ada ialah
-vacuum pump (utk vacuum pressure)
-resin reservoir tank
-big clear plastic bag (utk provide vacuum environment)
-vacuum hose, peel ply (nie wajib so that resin tak meleleh in excessive)
-breather (nie utk ease the resin flow ke dalam fiber cloth)
-sealant tape (utk seal vacuum plastic bag nnti)
briefly...
-memula korang kene sediakan molding area...on top of molding area tue mcm biasa lah, akan kene spray ngan gel coat n molding release agent (utk senang kuarkan parts dr mold bila dah siap)
-pastue korang prepare lah sandwich construction...haku dah explain amende sandwich construction kat previous post...
-on top of sandwich construction nie, biasa akan letak breather, followed by peel ply...breather nie mudahkan resin flow while peel ply prevent resin tue dr flowing excessively on to the surface...so that thickness resin tue maintain uniform...
-kat tepi2 area sandwich construction nie, on top of the mold, korang letak spiral tubing..spiral tubing nie akan connected to vacuum outlet line, which is then connected to resin trap or resin reservoir tank then goes into vacuum pump
-kat tengah2 molding tue, on top of the peel ply (bawah tue ada breather ngan sandwich), korang taruk resin inlet line, which is connected to baldi penuh ngan resin....line resin nie korang kene clamp dulu lah, jgn bagi resin naik
-lepas sume nie siap, korang kene bungkus sume tue pakai plastic bag...semua inlet ngan outlet line kene seal betul2...especially resin inlet ngan vacuum outlet...tepi2 molding tue lak also wajib kene seal so that tight vacuum pressure is maintained...
-this time, jgn bukak dulu resin line...instead bukak vacuum line dulu so that semua
udara dlm plastic bag tue kene sedut keluar....normally nie akan dibiarkan dlm masa 30minit to 2 or 3 jam depending ngan saiz molding tue...masa nie la korang kene check betul2 so that takde leak kat bag tue...otherwise nnti mold rosak....
-lepas sure xde leak, now korang kene bukak clamp kat resin input line...nnti korang tgk resin tue flow into the vacuum bag filling the sandwich construction then goes out thru vacuum line...any excessive resin will be trapped inside resin reservoir...
-masa nie korang nampak apa fungsi breather ngan spiral tubing tue...in tight vacuum condish plus limited flow due to fiber cloth, resin flow is assisted by the breather...breather nie basically cloth jek but allows better resin flow into the fiber...spiral tubing kat tepi2 molding lak utk sedut balik resin kuar thru vacuum line because resin inlet kat tengah2, so resin flow outward will proceed into spiral tubing...
anyway, cakap banyak pon tak guna...
heres some illustrations utk korang...
simple diagram utk vacuum resin infusion....plastic bag x tunjuk la coz mende tue akan cover semua nie
nie ada tunjuk vacuum bag...sacco tuh
lagi diagram..but nie kecik lah
schematic, but this one is called scrimp..basically an upgrade version of vacuum resin infusion..yg nie haku x sure sgt apa beza ngn conventional vacuum resin infusion..hopefully klu ader pro sini leh bitau sket2
vacuum infusion, hose tengah2 tue resin inlet line..kain putih tue peel ply, bawah tue sandwich construction lah...kaler hijau2 sket belah kiri tue resin tgh flowing outward
nampak cam tgh wat bumbung kete jekk...hehehehe
nie vacuum resin infusion utk wat hull race sailboat...derang pakai foam core..kat tengah2 hose tue ada breather arr...mende putih rectangle...nampak clear ader part basah n ader part kering...basah tue sbb resin tgh flow, kering lak resin x sampai lagi...tricky part is to guess the right amount of resin flowing at the same rate to all directions
antara equipment utk VIR...hitam besa tu vacuum pump..ade hose, gel coat/mold release agent, 2 bijik clamp, breather (gray), peel ply (putih), lagi satu tue vacuum bag, ngan sealant tape
buat hull sailboat....sbb bentuk sailboat nie bentuk U...so assisting channels kene ada, mcm hos kecik2 forming U shapes along the hull...so that easy sket resin nak flow..otherwise kene tunggu until 30th century baru siap...hahahaha
demo video teknik vacuum resin infusion utk mold bonet (ke boot???) kete...hehehehe
pdf file utk teknik nie, briefly lah
www.fibreglast.com/documents/361.pdf
composite material bukan saja merujuk kpd bhn2 plastik dan fibre tetapi juga semua jenis campuran bahan2 secara fizikal yg tidak bergabung secara kimia. cthnya, lantai concrete yg merupakan gabungan antara simen dan dawai keluli merupakan sejenis bahan komposite. itulah sebabnya jp morgan chase tower merupakan bangunan komposit tertinggi didunia kerana ia mengunakan simen dan batang keluli. brlawanan dgn kebanyakan bangunan tinggi lain di dunia spt menara petronas, world trade centre (yg roboh semasa 9-11) dibuat dari keluli sepenuhnya dan konkrit hanya digunakan utk membuat lantai setiap tingkat saja. gabungan 2 atau lebih bahan dlm komposit adalah utk melengkapi kekurangan yg lain. simen sgt kuat menahan daya mampatan(compression) tapi tidak mampu menanggung beban daya regangan(tension) jadi tension load diambil oleh keluli. begitu juga figreglass cthnya: gentian kaca menahan tension dan resin menahan compression. kelemahan utama bahan komposit yg dibuat dari fibre reinforced polymers(FRP) adalah kebanyakannya ianya tidak mempunyai kekuatan tambahan lebih dari design load. berlawanan dgn logam yg design loadnya dibuat dlm elastic region. bila melampaui elastic region ia akan mengalami plastic deformation. beban yg diperlukan utk memathkan sesuatu bahan logam dari plastic region ke fracture point sgt besar amnya jadi sesuatu komponen yg dibuat dari logan akan tetap utuh dan tidak patah walaupun dah senget atau herot. bagi FRP pula failure modenya lebih cepat bila melepasi design load. kejadian meletupnya space shuttle colombia adalah kerana sayap carbon fibrenya pecah sedikit sewaktu berlepas terkena impak. sewaktu fasa re-entry sayapnya patah menyebabkan kapal angkasa berkenanaan meletup.
i have a few questions regarding the amount of composite materials utilized in the construction of this so called AlBuruj tower:
well ...how much amount of composite materials involved in this megaproject?
2) would this project necestes the usage of different form of composites?
if yes ..in what way ...and why?
oh ya since we are dealing with material sciences ni, wanna ask something
on the selection of materials involve in making the Stealth Bomber F- series fighter planes?
how woud the team choose the radar -proof materials - ?
what 's the term ntah ..i dh lupa ni SARAH RADZI tahu...
Post time 5-2-2008 07:20 PM
变色卡
Author
