SECTION A : 100 MARKS BAHAGIAN A : 100 MARKAH INSTRUCTION: This section consists of SIX (6) essay questions. Answer FOUR (4) questions only.

SECTION A : 100 MARKS BAHAGIAN A : 100 MARKAH INSTRUCTION: This section consists of SIX (6) essay questions. Answer FOUR (4) questions only. ARAHAN : Bahagian ini mengandungi ENAM (6) soalan esei. Jawab EMPAT (4) soalan sahaja. QUESTION 1 SOALAN 1 CLO 1 C (a) Explain and sketch the suspension and balancer methods to determine the center of gravity of vehicles. Nyatakan dan lakarkan kaedah gantungan dan keseimbangan yang digunakan untuk menentukan kedudukan pusat graviti kenderaan. [10 marks] [10 markah] CLO 1 b) Derive the equation to determine the height center of gravity h c when a vehicle is descending a hill at α angle. Terbitkan formula untuk mendapatkan ketinggian pusat gravity hc apabila sebuah kenderaan sedang menuruni bukit pada kecondongan sudut α. [15 marks] [15 markah] SULIT

QUESTION SOALAN CLO1 (a) Sketch and explain the various harmonics of radial non-uniformities in tire / wheel assembly caused by imperfection in tire shape. Lakar dan terangkan pelbagai harmonic jejarian bukan seragam dalam sambungan tayar / rim yang disebabkan ketidak-sempurnaan dalam bentuk tayar. [10 marks] [10 markah] CLO1 (b) A car has specific parameters as shown below: Tire vertical stiffness @ tire rate, K t Kekerasan menegak tayar @ kadar tayar, K t Front suspension stiffness / Kekerasan suspensi depan, K sf Rear suspension stiffness / Kekerasan suspensi belakang, K sr Mass of car / Jisim kereta, m c 50 KN/m 5 KN/m 0 KN/m 1000 kg i) Calculate the front and rear suspension ride rate. Kirakan kadar tunggangan bagi suspensi depan dan belakang ii) Estimate the natural frequency of two suspensions (front & rear) if 60% of car load had been supported by the front wheels. Anggarkan frekuensi natural bagi dua suspensi (depan & belakang) sekiranya 60% beban kereta ditampung oleh tayar depan. [15 marks] [15 markah] 3 SULIT

QUESTION 3 SOALAN 3 CLO C1 (a) Give THREE(3) basic functions of tires which contribute to the vehicle dynamic aspect. Berikan TIGA(3) fungsi asas tayar yang mana menyumbangkan kepada aspek dinamik kenderaan. [6 marks] [6 markah] CLO (b) By referring to Figure 3.1, find the deflected zone area of the tire for the following cases : Merujuk pada Rajah 3.1, cari luas kawasan pesongan tayar bagi kes-kes berikut :- 50 mm Figure 3.1 / Rajah 3.1 (i) At full contact, when ϒ = 0 / Pada sentuhan penuh, apabila ϒ = 0 ; [3 marks] [3 markah] (ii) At full contact, when ϒ = 5 / Pada sentuhan penuh, apabila ϒ = 5 ; [3 marks] [3 markah] 4 SULIT

CLO C (c) (iii) At partial contact, when ϒ = 5 if rsr = 115 mm Pada separa sentuhan, apabila ϒ = 5 jika rsr = 115 mm ; [3 marks] [3 markah] With aid of a diagram, explain the contact points at both full and partial contacts. Dengan bantuan gambar rajah, terangkan titik sentuhan bagi keseluruhan dan separa sentuhan. [10 marks] [10 markah] 5 SULIT

QUESTION 4 SOALAN 4 CLO (a) A formula one (F1) car is equipped with specified wings in order to produce the aerodynamic forces and torques. Details below show the specifications of an F1 car: m = 64 kg V = 00 km/h L = 3050 mm F AR = 500 N h = 170 mm Weight distribution (front/rear) = 45/55 * Down force at 00 km/h ~ same as vehicle weight Determine the axle loads for front and rear wheels if the F1 car accelerates from 00 km/h to 300 km/h in 3 seconds. Given the equations of motion as follows: F a h a1 h FD 1 mg( ) ( mv F ) Fz FD mg( ) ( mv FAR ) a a a a a a a a z1 AR 1 1 1 1 Kereta Formula 1 (F1) telah dipasang dengan sayap yang spesifik untuk menghasilkan daya-daya aerodinamik dan daya kilas. Spesifikasi F1 ditunjukkan seperti maklumat berikut: F m = 64 kg V = 00 km/h L = 3050 mm F AR = 500 N h = 170 mm Nisbah berat (depan/belakang) = 45/55 * daya ke bawah pada 00 km/h ~ sama seperti berat kenderaan Tentukan beban gandar untuk tayar hadapan dan belakang jika kereta F1 memecut dari kelajuan 00 km/j hingga 300 km/j dalam masa 3 saat. Diberi persamaan gerakan seperti berikut: a h a1 h FD 1 mg( ) ( mv F ) Fz FD mg( ) ( mv FAR ) a a a a a1 a a1 a z1 AR 1 1 [13 marks] [13 markah] 6 SULIT

CLO (b) Based on the simple vehicle model as shown in Figure 4.1, name all forces on each point given shown by the alphabets A to J. Berdasarkan kepada model kenderaan ringkas dalam Rajah 4.1, namakan setiap daya pada setiap titik yang diberikan. A B C D E F G H I J Figure 4.1 / Rajah 4.1 [5 marks] [5 markah] CLO (c) Rewrite the equation of motion in the x-plane, z-plane and also moment at the center of gravity for the figure given in question 4 (b). Lanjutan daripada gambarajah di atas, sila tulis semula persamaan gerakan di dalam paksi-x, paksi-z dan juga momen di pusat graviti. [7 marks] [7 markah] 7 SULIT

QUESTION 5 SOALAN 5 CLO3 C (a) Describe briefly the kinematic tire model. Nyatakan secara ringkas tentang model tayar kinematik. [6 marks] [6 markah] CLO3 (b) Formulate the equation of motion for the velocity at the following conditions. i) at the real axle ii) at the front axle Rumuskan persamaan gerakan bagi halaju pada keadaan berikut : (i) Pada gandar belakang (ii) Pada gandar hadapan [10 marks] [10 markah] CLO3 C (c) Explain briefly the steady state cornering performance of a vehicle at the following conditions: i) Neutral Steer ii) Understeer Steer iii) Oversteer Steer Terangkan secara ringkas steady state cornering bagi kenderaan pada keadaan berikut : i) Neutral Steer ii) Understeer Steer iii) Oversteer Steer [9 marks] [9 markah] 8 SULIT

QUESTION 6 SOALAN 6 CLO 3 C a) Figure 6.1 shows steering angle (deg) vs time(s) graph for step steer input. Describe FIVE (5) characteristics of the step steer input. Rajah 6.1 menunjukkan graf sudut stereng (deg) melawan masa(s). Huraikan LIMA (5) ciri-ciri bagi step steer input. [10 marks] [10 markah] Figure 6.1 / Rajah 6.1 CLO 3 C1 b) Label the right terms for the following Figure 6. of step steer input from (i) to (viii): Labelkan istilah/label yang betul bagi Rajah 6. step steer input yang berikut dari (i) hingga (viii): [8 marks] [8 markah] 9 SULIT

i) ii) iii) v) 10 SULIT

v) vi) vii) viii) Figure 6. / Rajah 6. 11 SULIT

CLO 3 C1 (c) Figure 6.3 compares the semi-trailing arm, single wishbone and trailing arm in the usage of rear axle for a passenger car. Rajah 6.3 membandingkan penggunaan semi-trailing arm, single wishbone dan trailing arm sebagai gandar belakang bagi sesebuah kenderaan. [7 marks] [7 markah] Single wishbone Semi trailing arm Trailing arm Figure 6.3 / Rajah 6.3 SOALAN TAMAT 1 SULIT