dinamica autobasculanta

8/13/2019 Dinamica autobasculanta

1/34

PREDEFINED DIMENSIONS

kg 1 kg s 1 s m 1 m

min 60s hr 3600s km 1000m rpm 0.1051

s

kph 1 km

hr

N 1 N W 1 W J 1 J

DEFINED DIMENSIONS

rot 2 rad rot 6.283

rpm 1 rot

min

VEHICLE WEIGHTS & MASSES

Number of seats in front Nlocf 2

Mass of one passanger m1p 75kg

Baggage mass of one passanger mb1 25kg

Vehicle mass m0 13500kg

Front seat passanger mass (without

driver) mpf Nlocf 1 m1p mpf 75kg

Back load mass mis 16500kg

Mass of all passangers mp Nlocfm1p mp 150 kg

Baggage mass mb Nlocfmb1 mb 50kg

Useful mass mu mp mb mis mu 16700 kg

Total mass of the loaded vehicle mi m0 mu mi 30200 kg

Total weight of the loaded vehicle Gi mig Gi 296160.8

Gmum0

G 1.237Weight use coefficient

DIMENSIONAL PARAMETERS OF THE VEHICLE

Wheelbase Lam 4.8m

Gauge Bec 2.3m

Total height Hin 3m


2/34

MASSES REPARTITION - LOADED VEHICLE

Ratio between front axle weight and total weight

wi 0.22

Front axle weight

G1i wiGi G1i 65155.383 N

Back axle weight

G2i Gi G1i G2i 231005.447N

Weight on one wheel of the front axle

Gr1i

G1i

2 Gr1i 32577.691 N

Weight on one wheel of the back axle

Gr2i

G2i

2 Gr2i 115502.724 N

Horizontal length from center of gravity to back axle

bi Lamwi bi 1.056 m

Horizontal length from center of gravity to front axle

ai Lam bi ai 3.744 m

Center of gravity height

hi 1.2m

MASSES REPARTITION - UNLOADED VEHICLE

Unloaded vehicle mass

md mi mpf mis mb md 13575 kg

Unloaded vehicle weight

Gd mdg Gd 133125.274 N


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Horizontal positions of the masses with respect to the front axle

Front passanger apf 0.56m

Back load ais 2.37m

Baggage ab 0.25m

Vertical positions of the masses with respect to the front axle

Front passanger hpf 1.86m

Back load his 1.5m

Baggage hb 1.5m

Horizontal position of the center of gravity for unloaded vehicle

ad

miai mpf apf misais mbab

md

ad 5.445 m

Vertical posit ion of the center of gravity for unloaded vehicle

hd

mihi mpfhpf mishis mbhb

md

hd 0.831 m

Ratio between front axle weight and total weight:

wd

Lam ad

Lam

wd 0.134

Front axle weight

G1d wdGd G1d 17875.276 N

Back axle weight

G2d Gd G1d G2d 151000.549 N

Weight on one wheel of the front axle

Gr1d

G1d

2 Gr1d 8937.638 N

Weight on one wheel of the back axle

Gr2d

G2d

2 Gr2d 75500.275 N


4/34

TYRE CHOICE

Highest load on one wheel

Gmax max Gr1iGr2i Gmax 115502.724 N

Based on the maximum load on the wheel, the following tyres are chosen:

285/70 R19.5, with the following characteristics:

Tyre width Btyre 285mm

Aspect ratio Asptyre 70% Asptyre 0.7

Rim diameter Djanta 19.5 in Djanta 495.3 mm

Tyre height Htyre BtyreAsptyre Htyre 199.5 mm

Free radius r0

Djanta

2Htyre r0 447.15 mm

Deformation coefficient of the tyre 0.95

Dynamic radius rd r0

rd 424.793 mm

Jr 60kg m2

Vehicle transmission characteristics

estimated efficiency est 0.90

Aerodynamic characteristi cs of the vehic le

aerodynamic drag coefficient

cx 0.7

Front surface area

Sair BecHin Sair 6.9m2


5/34

MOVEMENT CONDITIONS

Total road resistance coefficient

f ( ) f cos ( ) sin ( )

Normal road conditions

Aerodynamic condi tions for maximum speed

Air density

air 1.225

kg

m3

Aerodynamic coefficient of the vehicle

kair

aircx

2 kair 0.429

kg

m3

Road conditi ons for maximum speed - horizontal road

v 0 grade angle

fv 0.016 rolling resistance coefficient

v fv v v 0.016 total road resistance coefficientv 0.9 grip coefficient - dry road

Roughest road conditions

maxN 17deg 100 tan maxN 30.573 % maximum grade angle

fN 0.016

maxN fN maxN maxN 0.308 total road resistancecoefficient

N 0.7

Dynamic load coefficient

Normal road conditions

mNmni

Lam

Lam Nhi cos maxN mNmni 1.159


6/34

GRADE ABILITY

maxmm hg a atan a

Lam hg

ad 0 0.05 0.9

0 0.2 0.4 0.6 0.80

10

20

30

40

Tract. spate inc.

Tract. spate desc.

Maximum grade

maxmm adhi ai deg

maxmm adhd ad deg

ad

Resistant power and forces

Aerodynamic resistance force Rava( ) kairSair va2

Rolling resistance force Rr( ) fvGi cos ( )

Grade resistance Rp ( ) Gisin ( )

Total resistance force Rtotva ( ) Rr( ) Rp ( ) Rava( )

Air resistance power Pava( ) Rava( ) va

Rolling resistance power Prva ( ) Rr( ) va


7/34

Grade resistance power Ppva ( ) Rp ( ) va

Ptotva ( ) Rtotva ( ) vaTotal resistant power

Necessary power for maximum speed

vmax 110km

hr

Air resistance power

Pav Pavmax Pav 84.396 kW

Rolling resistance power

Prv Prvmax v Prv 144.79 kW

Necesarry wheel power for maximum speed

PRtv Ptotvmax v PRtv 229.186 kW

Necessary engine power for maximum speed

Pvmax

PRtv

est

Pvmax 254.651 kW

The following engine is chosen:

PN 241kW

n

N

2350rpm

MM 810N m

nM 1600rpm

MN

PN

nN

MN 979.311 N m

PM MMnM PM 135.717 kW

cenMnN

ce 0.681

ca

MM

MN

ca 0.827

nmin 500 rot

min

nmax 1.07 nN nmax 2514.5 rot

min

Jm 2.4kg m2


8/34

Np

800

900

1000

1100

1200

1300

1400

1500

1600

1700

1800

1900

2000

2100

2200

2300

2350

2400

rot

min Mp

620.14

650.20

680.59

710.30

730.56

750.89

770.45

790.34

810.20

790.34

780.23

767.98

755.20

730.43

700.43

680.23

675.65

660.54

N m

Coef cspline Np Mp( )

Mextn( ) interp Coef Np Mp n( ) Mregn( )nmax n

nmax nN MN

M n( ) if n nN Mextn( ) Mregn( )


9/34

Engine power is obtain

P n( ) M n( ) n

SPECIFIC FUEL CONSUMPTION

The following parameters are adopted:

cN 280 gm

kW hr

specific fuel consumption at nominal engine speed

11 1.55 21 1.55 31 1

HOURLY FUEL CONSUMPTION

ChN cNPN ChN 67kg

hr Chg

ChN

3 Chg 22.493

kg

hr

c1ene cN 11 21ne

nN

31

ne

nN

2

nc nmax 20rpm

Chne if ne nN c1ene P ne Chg ChN Chg nmax ne

nmax nN

cene if ne ncChne P ne

Chnc P nc

n nminnmin 150rpm nmax

500 1000 1500 2000 25000

200

400

600

800

1000

M n( )

N m

P n( )

kW4

Chn( )kg

hr

cen( )

kg

kW hr

500

n

rpm


10/34

TRANSMISSION EFFICIENCY

cv1 0.975 0.98 cv4 0.975 0.98 cv1 0.955

cv2 0.975 0.98 cv5 0.975 0.98 cvE 0.975

cv3 0.975 0.98

cvV 0.98 pl 0.993

Transmission efficiency:

direct drive: trV cvVpl trV 0.973trE cvEpl trE 0.968economical gear:

tr1 cv1 pl tr4 cv4 pl

tr2 cv2 pl tr5 cv5 pl tr7 trE

tr3 cv3 pl tr6 trV

Maximum speed of the vehicle

nvmax 0.98 nN nvmax 2303 rot

min

Pvmax P nvmax Pvmax 163.981 kW

Term: Av

Gi v

kairSair Av 1.602 10

3

m

s

2

Bv

trVPvmax

kairSair Bv 53940.702

m3

s3

Term:

vmax

3

Bv

2

Bv

2

2Av

3

3

3

Bv

2

Bv

2

2Av

3

3


11/34

vmax 88.191km

hr

Transmission ratios of the gearbox

It is adopted a transmission ratio for the direct drive:

icvV 1

i0

nvmaxrd

icvVvmax i0 4.182

N 0.8

mNmni

Lam

Lam Nhi

Transmission ratio of the first gear:

trN 0.893

Gi maxN rd

MM trN i0 12.796

mNmniGi N rd MM trN i0

41.59

GimaxR rd10 3

MM trN i0 icv1

mRmniGi N rd10 3

MM trN i0

icv1 6


12/34

q0

nN

nM 130 rot

min

q0 1.358

Necessary number of gears for starting (with no economical gear):

Ntr 1

lnicv1

icvV

ln q0

Ntr 6.85

It is adopted the number of gears including the economical gear:

Ntr 7

q

Ntr 2

icv1icvV

q 1.431

Transmission ratios of the gears:

icv1 q5

6 icv4 q2

2.048 icv71

q0.699

icv2 q4

4.193 icv5 q 1.431

icv3 q3

2.93 icv6 1

Coefficients of the masses in rotational movement:

Determining the equivalent masses:

Jmoticv masa 1Jmot icvi0

2 Jr

masa rd2

1i Jmicv1 mi 1i 1.288 1d Jmicv1 md 1d 1.641







ai Jm

100icv7 mi

ai 1.011 ad

Jm

100icv7 md

ad 1.025


13/34

Speed in functi on o f the gear:

v1n( ) nrd

icv1i0 v2n( ) n

rd

icv2i0 v3n( ) n

rd

icv3i0

v4n( ) nrd

icv4i0 v5n( ) n

rd

icv5i0 v6n( ) n

rd

icv6i0

v7n( ) nrd

icv7i0

Gears changing during launching

n1min nM n1max nN n1max 2350 rot

min

n2min n1max

icv2

icv1

n2min 1642 rot

min n2max nN

n3min n2max

icv3

icv2

n3min 1642 rot

min n3max nN

n4min n3max

icv4

icv3

n4min 1642 rot

min n4max nN

n5min n1max

icv5

icv4

n5min 1642 rot

min n5max nN

n6min n1max

icv6

icv5 n6min 1642

rot

min n6max nvmax n6max 2303 rot

min


14/34

Gear changing depending on the speed of the vehicle

v1min v1n1min v1min 10.212km

hr v1max v1n1max v1max 14.999

km

hr



km

hr



km

hr


hr

v4max v4n1max v4max 43.948km

hr



km

hr



km

hr


15/34

500 1000 1500 2000 25000

100

200

300

Speed characteristic

v1max

kph

v2max

kph

v3max

kph

v4max

kph

v5max

kph

v6max

kph

v1n( )

kph

v2n( )

kph

v3n( )

kph

v4n( )

kph

v5n( )

kph

v6n( )

kph

M n( )

3N m

P n( )

kW

n

rpm


16/34

v 0km

hr 1

km

hr 1.2vmax

Traction abil ity

FR1n( )M n( ) trN i0 icv1

rd


rd


rd


rd


rd


rd


rd

0 25 50 75 100 125 150 1750

10000

20000

30000

FR1n( )

N

FR2n( )

N

FR3n( )

N

FR4n( )

N

FR5n( )

N

FR6n( )

N

FR7n( )

N

Rrv N

v1n( )

kph

v2n( )

kph

v3n( )

kph

v4n( )

kph

v5n( )

kph

v6n( )

kph

v7n( )

kph


17/34

Power characteristic

Power at the wheel for each gear:

PR1n( ) P n( ) tr1 PR2n( ) P n( ) tr2 PR3n( ) P n( ) tr3

PR4n( ) P n( ) tr4 PR5n( ) P n( ) tr5 PR6n( ) P n( ) tr6

PR7n( ) P n( ) tr7

0 25 50 75 100 1250

31.667

63.333

95

126.667

158.333

190

Power characteristic

P n( )

kW

PR1n( )

kW

PR2n( )

kW

PR3n( )

kW

PR4n( )

kW

PR5n( )

kW

PR6n( )

kW

PR7n( )

Ptotv a kW

Ptotv d kW

v6n( )

kph

v1n( )

kph

v2n( )

kph

v3n( )

kph

v4n( )

kph

v5n( )

kph

v6n( )

kph

v7n( )

kph


18/34

Dynamic characterist ic

D1n( )

FR1n( ) kairSair v1n( )2

Gi D2n( )

FR2n( ) kairSair v2n( )2

Gi

D3n( )FR3n( ) kairSair v3n( )

2

Gi


2

Gi


2

Gi


2

Gi


2

Gi

0 50 1000

0.1

0.2

0.3

Dynamic characteristic

D1n( )

D2n( )

D3n( )

D4n( )

D5n( )

D6n( )

D7n( )

v1n( )

kph

v2n( )

kph

v3n( )

kph

v4n( )

kph

v5n( )

kph

v6n( )

kph

v7n( )

kph


19/34

Maximum grade depending on the gear:

max1n( ) 2 atan

1 1 fv2

D1n( )2

fv D1n( )

max2n( ) 2 atan

1 1 fv2

D2n( )2

fv D2n( )

max3n( ) 2 atan1 1 fv

2 D3n( )

2

fv D3n( )

max4n( ) 2 atan

1 1 fv2

D4n( )2

fv D4n( )

max5n( ) 2 atan1 1 fv

2 D5n( )

2

fv D5n( )

max6n( ) 2 atan

1 1 fv2

D6n( )2

fv D6n( )

max7n( ) 2 atan

1 1 fv2

D7n( )2

fv D7n( )

max1nM 7.374 deg 100 tan max1nM 12.942 %

0 50 100

0

2

4

6

8

max1n( )

deg

max2n( )

deg

max3

n( )

deg

max4n( )

deg

max5n( )

deg

max6n( )

deg

max7n( )

deg

0

v1n( )

kph

v2n( )

kph

v3n( )

kph

v4n( )

kph

v5n( )

kph

v6n( )

kph

v7n( )

kph

v

kph


20/34

Acceleration diagram

a1n( ) gD1n( ) v

1i

a2n( ) gD2n( ) v

2i

a3n( ) gD3n( ) v

3i

a4n( ) gD4n( ) v

4i

a5n( ) gD5n( ) v

5i

a6n( ) gD6n( ) v

6i

a7n( ) gD7n( ) v

7i

0 50 100

0

0.5

1

a1n( )

m

s2

a2n( )

m

s2

a3n( )

m

s2

a4n( )

m

s2

a5n( )

m

s2

a6n( )

m

s2

a7n( )

m

s2

0

m

s2

v1n( )

kph

v2n( )

kph

v3n( )

kph

v4n( )

kph

v5n( )

kph

v6n( )

kph

v7n( )

kph

v

kph


21/34

Engine speed for optimum launching

n1max nN

Given

a1n1max a1 n1maxicv2

icv1

=

n1max Find n1max n1max 2350 rpm

n2max nN

Given

a2n2max a2 n2maxi

cv3icv2

=


n3max nN

Given


icv3

=


n4max nN

Given


icv4

=


n5max nN

Given


icv5

=

n5max Find n5max n5max 2350 rpmn6max nN

Given


22/34


23/34

0 50 1000

1

2

3

avv( )

avvdem

v

kph

Launching time

Launching time depending on speed

t

d

va( )

0

va

va1

avva( )

dtdtot tdvdem tdtot 250.763 s

Launching time until 100 km/h:

td 100 km

hr

td 100

km

hr


24/34

0 20 40 60 800

100

200

300

tdvd s

td100 kph( )

s

vd

kph

Launching space

Sdva( )

0

va

vava

avva( )

d Sdtot Sdvdem Sdtot 4539.427m

0 16 32 48 64 800

500

1000

1500

2000

2500

Sdvd m

500

1000

vd

kph

Speed at which the clutch is coupled:

v1min 10.212 kph


25/34

Clutch slipping time:

t

d

v

1min 2.281 s

Distance until the clutch is coupled:

Sdv1min 3.235 mSpeed after 1 km after launching:

v1000 vdem

Given

Sdv1000 1000m=

v1000 Find v1000 v1000 64.254 kph

Time necessary for 1 km:

tdv1000 77.186s

Acceleration depending on launching time and space:

0 10 20 30 40 500

0.5

1

1.5

avvd m

s2

tdvd s

0 100 200 300 400 5000

0.5

1

1.5

avvd m

s2

Sdvd m

Speed depending on launching time and space:

0 50 1000

20

40

60

80

vd

kph

tdvd s

0 500 1000 1500 20000

20

40

60

80

vd

kph

Sdvd m


26/34

BRAKING ABILITY

BRAKING DECCELERATION

Coefficient of masses in rotational movement with uncoupled clutch:

br Jm0 mi

Sum of rections at the braked wheels:

Zbr mig

Braking force: Fbr( ) Zbr

Rolling resistance force Rr( )

Drag resistance force Rava

Grade resistance force Rp ( )

Decceleration

abrva 1

brmi Fbr( ) Rr( ) Rava Rp ( )


27/34

0 20 40 60 80

2

4

6

8abrva 0.2 0deg

m

s2

abrva 0.4 0deg m

s2

abrva 0.6 0deg m

s2

abrva 0.8 0deg m

s2

va

km

hr

BRAKING SPACE

Driver reaction time tdr 0.8sBraking system reaction time

tsys 0.54sttotal tdr tsys Considering driver reaction timeTotal reaction time:ttotal2 tsys Neglecting driver reaction time

Braking space:

sstopva vattotal brmi

0

va

va

va

Fbr( ) Rr( ) Rava Rp ( )

d

sstop2va vattotal2 brmi

0

v

ava

va

Fbr( ) Rr( ) Rava Rp ( )

d


28/34

0 10 20 30 40 50 60 70 80 90 100

25

50

75

100

125

150

175

200

225

250

sstopva 0.2 0deg

m

sstopva 0.4 0deg m

sstopva 0.6 0deg m

sstopva 0.8 0deg m

sstop2va 0.2 0deg

m

sstop2va 0.4 0deg m

sstop2va 0.6 0deg m

sstop2va 0.8 0deg m

va

km

hr


29/34

CORNERING STABILITY

Critical slipping speed:

vdRv Rvg tan ( )

1 tan ( )

g gravity acceleration

Rv steering radius

transversal inclination of the road

grip coefficient

B.ec gauge

hg center of gravity height

0 50 100 150 200

20

40

60

80vdRaza 0deg 0.8( )

km

hr

vdRaza 0deg 0.6( )

km

hr

vdRaza 0deg 0.4( )

km

hr

vdRaza 0deg 0.2( )

km

hr

Raza

m

SPEED AT WHICH THE LOADED VEHICLE

TURNS OVERS


30/34

vrlR ( ) R g

Bec

2hitan ( )

1Bec

2hi

tan ( )

SPEED AT WHICH THE UNLOADED

VEHICLE TURNS OVER

vrR ( ) R g

Bec

2hd

tan ( )

1Bec

2hd

tan ( )

0 50 100

20

40

60

80

Descarcat

Incarcat

vrRaza 0deg( )

km

hr

vrlRaza 0deg( )

km

hr

Raza

m


31/34

N


32/34


33/34

3

va

ri3

a4

va

ri4

if va v

5max a

5

va

ri5

a

6

va

ri6


34/34

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