DC063 : MECHANICS OF CIVIL ENGINEERING STRUCTURES SECTION A : 50 MARKS BAHAGIAN A : 50 MARKAH INSTRUCTION: This section consists of TWO (2) structured questions. Answer ALL the questions. ARAHAN: Bahagian ini mengandungi DUA (2) soalan berstruktur. Jawab SEMUA soalan. QUESTION 1 SOALAN 1 CLO1 C1 (a) Describe direct stress and direct strain. Terangkan tegasan terus dan terikan terus. CLO1 (b) A rectangular bar of 2m length with dimensions of 5mm width x 20 mm depth, supports a load of 4900 N. Sebatang bar panjang 2m, berkeratan segiempat tepat mempunyai dimensi 5mm lebar x 20mm dalam, dikenakan beban sebanyak 4900 N. i. Determine the stress in the bar. Tentukan tegasan di dalam bar tersebut [4 marks] [4 markah] ii. The bar is extended by 0.25mm when acted upon a tensile force. Determine the strain in the bar. Apabila dikenakan daya tegangan, bar tersebut telah memanjang sebanyak 0.25mm. Tentukan terikan di dalam bar. [4 marks] [4 markah] 2 SULIT
DC063 : MECHANICS OF CIVIL ENGINEERING STRUCTURES CLO1 (c) A steel column is 3m long and 0.4m diameter. It carries a load of 50MN. The modulus of elasticity given is 200 GPa. Sebatang tiang besi berdiameter 0.4m dan panjang 3m membawa beban sebanyak 50MN. Diberi modulus keanjalan ialah 200GPa. Kirakan: i. Calculate the compressive stress and strain in column Kirakan tegasan mampatan dan terikan dalam tiang ii. Determine how much the column length is compressed. Tentukan jumlah pemendekan tiang. [7 marks] [7 markah] QUESTION 2 SOALAN 2 C1 a) Define Principle Equlibrium Forces Takrifkan Prinsip Keseimbangan Daya [3 marks] [3 markah] b) Calculate the reaction force at each support of overhanging beam subjected to loads in Figure A2(a). Kirakan daya tindakbalas pada setiap penyokong bagi rasuk juntai apabila dikenakan beban dalam Rajah A2(a). [7 marks] [7 markah] Figure A2(a) / Rajah A2(a) 3 SULIT
DC063 : MECHANICS OF CIVIL ENGINEERING STRUCTURES c) A beam ABCD 4m long is overhanging by 1m and carries load as shown in Figure A2(b). Satu rasuk ABCD 4m panjang, terjuntai 1m dan menanggung beban seperti dalam Rajah A2(b). Figure A2(b) / Rajah A2(b) i. Draw the shear force and bending moment diagrams for the beam. Lukiskan gambarajah daya ricih dan momen lentur bagi rasuk tersebut. [11 marks] [11 markah] ii. Determine the point of contraflexure. Tentukan dimana titik kontra lentur [4 marks] [4 markah] 4 SULIT
DC063 : MECHANICS OF CIVIL ENGINEERING STRUCTURES SECTION B : 50 MARKS BAHAGIAN B : 50 MARKAH INSTRUCTION: This section consists of FOUR (4) structured questions. Answer TWO (2) questions only. ARAHAN: Bahagian ini mengandungi EMPAT (4) soalan berstruktur. Jawab DUA (2) soalan sahaja. QUESTION 1 SOALAN 1 A symmetrical I-section beam as shown in Figure B1 is subjected to a load of 60 kn and carries a uniformly distributed load of 15 kn/m along the whole span. Satu rasuk berkeratan I- semetri seperti dalam Rajah B1 menanggung beban 60 kn dan dikenakan beban teragih seragam 15 kn/m di sepanjang rasuk. 25 mm 60 kn 15 kn/m 25 mm 150 mm 25 mm A B C 4 m 4 m 150 mm Figure B1 / Rajah B1 (a) Determine the centroid for each axis. Tentukan kedudukan sentroid pada setiap paksi. [4 marks] [4 markah] 5 SULIT
DC063 : MECHANICS OF CIVIL ENGINEERING STRUCTURES (b) Determine the maximum moment for the beam. Tentukan momen lentur maksimum bagi rasuk [6 marks] [6 markah] (c) Calculate the bending stress for the beam cross section Nilai tegasan lentur untuk keratan rentas rasuk (d) Sketch the bending stress distribution diagram. Lakarkan rajah taburan tegasan lentur [10 marks] [10 markah] [5markah] QUESTION 2 SOALAN 2 The C-section of a beam that is shown in Figure B2 is subjected to shear force of 200kN. Rajah B2 menunjukkan keratan rentas bagi rasuk yang berbentuk C dan dikenakan daya ricih sebanyak 200kN. Figure B2/ Rajah B2 6 SULIT
DC063 : MECHANICS OF CIVIL ENGINEERING STRUCTURES a) Determine Neutral Axis of section Tentukan nilai paksi neutral keratan. b) Calculate Second Moment Area of the section. Kirakan nilai Momen Luas Kedua Keratan. c) Draw shear stress distribution of beam at a-a line and neutral axis point. Tentukan dan lukis taburan nilai tegasan ricih rasuk pada garisan a-a, dan paksi neutral. [15 marks] [15 markah] QUESTION 3 SOALAN 3 A simply supported beam (refer to Figure B3) of 9m span is loaded with two point loads of 20 kn and 10 kn at 2m and 5m from support A and a uniformly distributed load of 15 kn/m of 1m from support B. By using Macaulay Method, calculate : Sebuah rasuk disokong mudah (rujuk Rajah B3) yang mempunyai panjang 9m di kenakan dua beban tumpu iaitu 20 kn dan 10 kn pada jarak 2m dan 5m setiap satunya dari penyokong A. Beban teragih seragam 15 kn/m dibebankan sepanjang 1m dari penyokong B. Dengan menggunakan Kaedah Macaulay, kirakan : (a) Reaction at both supports. Tindak balas bagi kedua-dua penyokong. 7 SULIT
DC063 : MECHANICS OF CIVIL ENGINEERING STRUCTURES (b) The deflection and slope at point C in term of EI. Pesongan dan kecerunan pada titik C dalam sebutan EI. [20 marks] [20 markah] Figure B3 / Rajah B3 QUESTION 4 SOALAN 4 CLO1 C1 a) i. Define structure in Civil Engineering. Takrifkan struktur dalam Kejuruteraan Awam. [2 marks] [2 markah] ii. With the aid of the diagram the direction of reaction for roller, pinned and fixed end support. Dengan bantuan gambarajah labelkan arah tindak balas bagi penyokong rola, pin dan hujung terikat. [3 marks] [3 markah] 8 SULIT
DC063 : MECHANICS OF CIVIL ENGINEERING STRUCTURES b) A simply supported beam is subjected to a point load as shown in Figure B4(a). Calculate the reaction force at each support and the value of bending moment at P,Q,R,S. Satu rasuk disokong mudah dikenakan beban tumpu seperti dalam Rajah B4(a). Kirakan tindak balas pada setiap penyokong dan nilai momen lentur pada P,Q,R,S. Figure B4(a) / Rajah B4(a) c) An overhanging beam ABC is loaded as shown in Figure B4(b). Calculate the deflection at point D by using Moment Area Method. Take E = 2x10 5 N/mm 2 and I = 5x10 8 mm 4. Satu rasuk juntai ABC mempunyai beban seperti dalam Rajah B4(b). Kirakan pesongan pada titik D dengan menggunakan Kaedah Momen Luas. Ambil nilai E = 2x10 5 N/mm 2 and I = 5x10 8 mm 4. [15 marks] [15 markah] Figure B4(b) / Rajah B4(b) SOALAN TAMAT 9 SULIT