صفحه 1:
صدا و ارتعاش در صنعت
جلسه دوم
محمد رضا منظم
mmonazzam@hotmail.com
صفحه 2:
eo
مروري بر ریاضیات
صفحه 3:
2 Real Numbers
at(btd=(atD+c , 240-6
atb=b+a_ , ab=ba
db+d=abtac , اك bay
Ava sa
صفحه 4:
mt 1
ea
4 Indices
(at) تم a =a Faden =a aes
صفحه 5:
Logarithms
yo=x ee n=log, vy
log| xy} =log,x+log,y , log, 3 ب 7ر10 1 رومت
log, x"| =mdog, x
el _ log, x
log, x= 7 log, * Tog, n
log, n
صفحه 6:
53 The Binomial Theorem
(a+ D? =a? +2ab+ b
(a+ D® =a? + 3a’b+ 3ab +B
ey ad جات ویر "و +ج)
dn- ( 9 2
)1+ بر ج... + لیر جرور +1- "لر n>0
dn- 1(...)0- و(
2
(14+ 9” =1+ nx+...+ all n
صفحه 7:
2 Trigonometry
0 6010 - 0 , cosed = 2 ار 9008 1
cod tam sing
003
6)=-sin, co$- 6) =co#, tat 6) =- tam نزو
sir’ 9+cos @ =1
1+ tari م6 =secéa
cot @ +1=coseca
صفحه 8:
Trigonometry (continue..)
it A+B =sinAcosB+cosdsinB co$A+B =cosAcosBFsinAsinB
00 ا
1+tanAtanB
1 4 ۰ 2tanA
co@A=cos A- sit A sin2A=2sinAcos4 tarA=.
1- tart A
J 4 1 2
3 ۰ 78 = 3 ۳ X+ 23
SURE SIY بای sinx- SHY رت
cosx+ cosy=2cos=-* cos”, 005 005۲ - مور sinX ال
صفحه 9:
Radian Measure
360 =27 raa 240 =* rad
cos? =0, > @ =nt
ifsim) =sina= 0 وع +) ۵
if cos) =cosa> 0 =2m +a
iftam=tam = @=m+a
a x
x=sim) = 0=sin'x ع وت
2 2
x=cos = @ =cos'x 0-6 >>
xstaw = 0 =tan'x pee gre
2 2
صفحه 10:
Complex Numbers
¥64=8-8 y= 64=8/-1 1 04-9
fol pai از <1
اه رم لت لح سا ها موه ویو
Z=a+ jb
Oukexvuncd operatic ty موی او با نوا ec.
ie cone (a+ jBlc+ jd =(ac- bd + fad+ bd
22 نه لال اك +
at jb_(a+ jhlc- jd _ و
c+ jd (c+ jdlc- jd e+ ne + Abe ad
لك ا 0ك )2 2125 )
صفحه 11:
Modulus (magnitude) and Argument
و
+ 22
ol ی ره
@=arg=tan'2 - > *>7
صفحه 12:
4 Polar Form of a Complex Number
= The argument can be written:
6098 ay sind -> - ۲ > >
4 3
= Therefore
z=|Acos) + jsind)
ZZ, =|z\|z,| coo, +0,)+ jsio, +0,)|
A ا - 6) + jsila, - آ(یه
2 |Z
صفحه 13:
Polar Form of a Complex
2
Ce et ata
2!
cosx=1- = tea 13 oe we
a a! ۳
9
eel (red!
(cers Pore)
بت رح زو
OSB
R xbyjo in thee*
2 pf
تس ۳ -1|- ام
2 4
Boor AS
0- م 7
ا
=cos# + jsind
aa
صفحه 14:
Polar Form of a Complex Number
(continue)
= Zcan be written as:
ae 0
لور دج
مصزوز + ومع و
jsind -وووع و
مرج - 6
sing SOs eae
2
e+e”
cos? =
2
صفحه 15:
Fourier Analysis
(Joseph Fourier (1706-1790)
* Fourier series
It enables periodic functions to be represented by infinite
series of sine and cosine terms.
8 07م مع كر د
5 for a function
(Powter series Por te Rauctoa ضجا
fo gat dle cosit+ b, sinnot|
عا 2
an
a Dcosnwtdt اج رت
rs
2 فا
رك - sf sinmotdt
صفحه 16:
Fourier Analysis
(Joseph Fourier (1706-1790))
= Infinite Fourier Transform and inverse Fourier Transform
gsi] =Xo) = fle at
ecll 1 5 اس
é | X(a)] i dt
صفحه 17:
Fundamental concept
* Any moving form-some shape or pattern that travels along without
carrying all the medium with it.
Some type of wave:
Water wave
Wave on string- musical instrument
Mexican wave
Wind causing wave
Heat wave
Electromagnetic wave
Sound wave
صفحه 18:
Velocity, Frequency and wave length
ايا ومسي افا
i /۱ ۷ {\ re
5
a Hoque Hoe
i Te
nea
= The velocity of a wave (c):
the speed at which its
wave-form travels along,
the speed of any labelled
part of the disturbance.
" The frequency of a wave (f):
The number of oscillation it
makes in 1 second.
In 1 second the wave has
travelled "c” metres so that
"ع" metres contains “f”
cycles of the wave.
Hence in space one
complete wave is ¢/f metres
long (wavelength A)
The time of one oscillation
is the period (T)
c
a tod,
0 6
صفحه 19:
How Waves Travel
=" A wave travels essentially because:
= One piece of the medium disturbed by the wave
disturbs the next piece of medium ahead and
gives up the motion to it.
= The waves are:
= Longitudinal: The pieces of the medium oscillate in
the same direction as the wave propagate.
= Transverse: The pieces of the medium oscillate
perpendicular to the direction propagation of the
wave.
= Some other types including, Shear and Bending
صفحه 20:
Mathematical Description of
۳ Harmonic Wave
= The disturbance at x: at
time ti is due to the
disturbance at position xo
which occurred at time
to (% - x)
45 و
200080 وا - 0 < ود 01
صفحه 21:
4 Mathematical (continue)
= For harmonic waves ( plane wave):
انم بر Flot 0 2051117611132
S25 Axil 3 ct+ x) ۱ negativdirectic
20 xwures the wave repes every waveleonth
صفحه 22:
4 Mathematical (continue)
= Complete representation of a plane wave:
To allow the wave to have any value:
y= Axil (ct | + Boot (ct 3]
‘Pwe mt A=Dcosy) and — B=Dsirlg)
y=Dcoky) xsi (ct 5 + أده (ولشوط (ct a
, where D=V A’ +B andtap) =3
y=Dsif (ct ور +
صفحه 23:
۳ Mathematical (continue)
= Alternative equation for plane wave:
: ۶-9 and w=2f
ot- Fxeg فده دير
or
y=Cxsirlot- kx 9), k 00 (waveumber
صفحه 24:
۳ Mathematical (continue)
= Complex Representation
ae إلدع ار
یزرو A=A+jA
or
y=(4.+ JA) co} 2 (ct x + joi "Ect 01 and the real par.
ya Aco} 2 (op | Asi 2 (ct- a|
صفحه 25:
Examples (1)
= If the displacement of the particles of the
medium is described by:
0-0005 207 +
= What is the amplitude, frequency ,wavelength
and wave number and what is the speed of the
wave?
صفحه 26:
+ Examples (2)
= The pressure fluctuations in air are described
by:
p=0.01co$20G@t- 1.85x) + 0.005sir 20Gt- 59
= What is the amplitude, frequency, wavelength
and the speed of the wave.
صفحه 27:
4 Examples (3)
= The pressure, p, is described by:
p= +مالويم kt
= |f the pressure amplitude is 0.01 pa and at t=0
, X=0 the value of p is 0.005 pa find Ar and Ai.
صفحه 28:
{oe
Thanks for Listening