OLEH:
I MADE GATOT KAROHIKA, ST.MT
JURUSAN TEKNIK MESIN
FT – UNUD,
SEMESTER GENAP 2013-2014
Apa itu Mekanika?
Mekanika adalah ilmu yang menggambarkan dan
meramalkan kondisi benda yang diam atau bergerak
karena pengaruh gaya yang beraksi pada benda.
Mechanics
Rigid Bodies
(Things that do not change shape)
Statics
Dynamics
Deformable Bodies
(Things that do change shape)
Fluids
Incompressible
Compressible
Buku apa yang dipakai?
• F. P. Beer and E. R. Johnston Jr., Vector Mechanics for Engineers:
Statics, SI Metric Edition, Mcgraw-hill, atau
• F. P. Beer and E. R. Johnston Jr., Mekanika Untuk Insinyur :
STATIKA [TERJEMAHAN; VERSI INDONESIA]
• J.L Meriem, dkk, Engineering Mechanics, Statics, John Wiley &
Sons. Inc.
• J.L Meriem, dkk, MEKANIKA TEKNIK; STATIKA [indonesia]
• R. C. Hibbeler, Engineering Mechanics, 7th - 12th Edition, Person
Prentice-Hall
• Dll
• HARUS PUNYA SATU BUKU PEGANGAN DALAM
HARDCOPY
Bagaimana evaluasinya ?
•
•
•
•
•
•
TUGAS
: 10 %
AKTIF
: 20 %
Quis
: 20 %
UTS
: 20 % (sifat:………….)
UAS
: 30 % (sifat:………….)
Absensi >= 75%
: (Maksimal ketidak hadiran
dengan/tanpa alasan 3 kali).
• TIDAK ADA UJIAN SUSULAN!!!
HOW …. Kompetensi
KOGNITIF
PSIKOMOTORIK
AFEKTIF
MENIRU
JUJUR
MENGEMBANGKAN
RAJIN
MENYAMPAIKAN
PENDAPAT
PANTANG
MENYERAH
MEMAHAMI
MENGANALISA
TRANSFORMASI BELAJAR
ORIENTASI
BELAJAR
RUMUS JADI &
SOLUSI AKHIR
Pemodelan,
analisa,
solusi
SIKAP
BELAJAR
KOMUNIKASI
Kurang mandiri
dalam melatih
dan
mengembangkan
materi kuliah
Kurang berani
dan
tidak mampu
berkomunikasi
secara sistematis
Inisiatif mandiri
dalam melatih
dan
mengembangkan
materi kuliah
Berani dan
mampu
berkomunikasi
secara sistematis
Apa saja yang dipelajari?
I. INTRODUCTION
What is Mechanics?
Fundamental Concepts
Fundamental Principles
Systems of Units
Method of Problem Solution
Numerical Accuracy
2. STATICS OF PARTICLES
Introduction
Resultant of Two Forces
Vectors
Addition of Vectors
Resultant of Several Concurrent
Forces
Sample Problem 2.1
Sample Problem 2.2
Rectangular Components of a Force:
Unit Vectors
Addition of Forces by Summing
Components
2-8
Sample Problem 2.3
Equilibrium of a Particle
Free-Body Diagrams
Sample Problem 2.4
Sample Problem 2.6
Rectangular Components in Space
Sample Problem 2.7
3. RIGID BODIES: EQUIVALENT SYSTEM OF FORCE
Introduction
Moment of a Force About a Given Axis
External and Internal Forces
Sample Problem 3.5
Principle of Transmissibility: Equivalent Moment of a Couple
Forces
Addition of Couples
Vector Products of Two Vectors
Couples Can Be Represented By Vectors
Moment of a Force About a Point
Varigon’s Theorem
Rectangular Components of the
Moment of a Force
Resolution of a Force Into a Force at O
and a Couple
Sample Problem 3.6
Sample Problem 3.1
System of Forces: Reduction to a Force
and a Couple
Scalar Product of Two Vectors
Further Reduction of a System of Forces
Scalar Product of Two Vectors:
Applications
Sample Problem 3.8
Mixed Triple Product of Three Vectors
3-9
Sample Problem 3.10
4. Equilibrium of Rigid Bodies
Introduction
Free-Body Diagram
Reactions at Supports and
Connections for a TwoDimensional Structure
Equilibrium of a Rigid Body in Two
Dimensions
Statically Indeterminate Reactions
Sample Problem 4.1
Sample Problem 4.3
Sample Problem 4.4
Equilibrium of a Two-Force Body
Equilibrium of a Three-Force Body
Sample Problem 4.6
4 - 10
Equilibrium of a Rigid Body in Three
Dimensions
Reactions at Supports and Connections
for a Three-Dimensional Structure
Sample Problem 4.8
5. Distributed Forces: Centroids and Centers
of Gravity
Introduction
Theorems of Pappus-Guldinus
Center of Gravity of a 2D Body
Sample Problem 5.7
Centroids and First Moments of Areas
and Lines
Distributed Loads on Beams
Centroids of Common Shapes of Areas
Centroids of Common Shapes of Lines
Center of Gravity of a 3D Body:
Centroid of a Volume
Composite Plates and Areas
Centroids of Common 3D Shapes
Sample Problem 5.1
Composite 3D Bodies
Determination of Centroids by
Integration
Sample Problem 5.12
Sample Problem 5.4
5 - 11
Sample Problem 5.9
6. Analysis of Structures
Introduction
Definition of a Truss
Simple Trusses
Analysis of Trusses by the Method of
Joints
Joints Under Special Loading
Conditions
Space Trusses
Sample Problem 6.1
Analysis of Trusses by the Method of
Sections
6 - 12
Trusses Made of Several Simple Trusses
Sample Problem 6.3
Analysis of Frames
Frames Which Cease to be Rigid When
Detached From Their Supports
Sample Problem 6.4
Machines
7. Forces in Beams and
Cables
Introduction
Sample Problem 7.4
Internal Forces in Members
Sample Problem 7.1
Various Types of Beam Loading and
Support
Shear and Bending Moment in a
Beam
Sample Problem 7.2
Sample Problem 7.3
Relations Among Load, Shear, and
Bending Moment
7- 13
Sample Problem 7.6
Cables With Concentrated Loads
Cables With Distributed Loads
Parabolic Cable
Sample Problem 7.8
Catenary
8. FRICTION
Introduction
Square-Threaded Screws
Laws of Dry Friction. Coefficients of
Friction.
Sample Problem 8.5
Angles of Friction
Problems Involving Dry Friction
Sample Problem 8.1
Sample Problem 8.3
Wedges
8 - 14
Journal Bearings. Axle Friction.
Thrust Bearings. Disk Friction.
Wheel Friction. Rolling Resistance.
Sample Problem 8.6
Belt Friction.
Sample Problem 8.8
9. Distributed Forces: Moments of Inertia
Introduction
Moments of Inertia of an Area
Moment of Inertia of an Area by
Integration
Polar Moment of Inertia
Radius of Gyration of an Area
Sample Problem 9.1
Sample Problem 9.2
Parallel Axis Theorem
Moments of Inertia of Composite Areas
Sample Problem 9.4
Sample Problem 9.5
Product of Inertia
Principal Axes and Principal Moments
of Inertia
9 - 15
Sample Problem 9.6
Sample Problem 9.7
Mohr’s Circle for Moments and Products of
Inertia
Sample Problem 9.8
Moment of Inertia of a Mass
Parallel Axis Theorem
Moment of Inertia of Thin Plates
Moment of Inertia of a 3D Body by
Integration
Moment of Inertia of Common Geometric
Shapes
Sample Problem 9.12
Moment of Inertia With Respect to an
Arbitrary Axis
Ellipsoid of Inertia. Principle Axes of Axes
of Inertia of a Mass
10. Method of Virtual Work
Introduction
Work of a Force
Work of a Couple
Principle of Virtual Work
Applications of the Principle of Virtual Work
Real Machines. Mechanical Efficiency
Sample Problem 10.1
Sample Problem 10.2
Sample Problem 10.3
Work of a Force During a Finite Displacement
Potential Energy
Potential Energy and Equilibrium
Stability and Equilibrium
Sample Problems 10.4
10 - 16
Apa yang harus dilakukan supaya
Statika Struktur menjadi mudah ?
Banyak dan sering menyelesaikan soal-soal
Prosedur mengerjakan soal:
1. Baca soal dengan cermat
2. Buat free body diagram dan tabulasikan data soal
3. Tuliskan prinsip dasar / persamaan yang relevan dengan
soal
4. Selesaikan persamaan sepraktis mungkin sehingga didapat
hasil yang signifikan dan jangan lupa disertai sistem satuan
5. Pelajari jawaban dengan akal sehat, masuk akal atau tidak
6. Jika ada waktu, coba pikirkan cara lain untuk menyelesaikan
soal tersebut.