The document discusses different design philosophies for steel structures: 1) Allowable Strength Design (ASD) where required strength must be less than or equal to available strength divided by a safety factor. 2) Load and Resistance Factor Design (LRFD) where factored loads must be less than the design strength which is the nominal strength multiplied by a resistance factor. 3) ASD uses safety factors and load combinations while LRFD uses load and resistance factors along with load combinations. The document provides examples and equations to illustrate the relationships between loads and strengths for different design approaches.

1. Struktur baja
00 .Pengantar
01 .01. Karateristik Struktur baja
01. 02. Penampang profil baja
01. 03. Prinsip Desain
01. 04. Kriteria Desain Elemen Tarik
01. 05. Contoh 1. Kekuatan Elemen Tarik
01. 06. Contoh 2. Pemeriksaan Kekuatan Elemen Tarik (LRFD & ASD)
Materi 1
Materi 2
Materi 3

2. Struktur baja 1.3 Prinsip Desain
01
1. ASD (Allowable Strength Design)
The fundamental requirement of structural design is that the required strength not exceed the available strength.
𝑟𝑒𝑞𝑢𝑖𝑟𝑒𝑑 𝑠𝑡𝑟𝑒𝑛𝑔𝑡ℎ ≤ 𝑎𝑣𝑎𝑖𝑙𝑎𝑏𝑙𝑒 𝑠𝑡𝑟𝑒𝑛𝑔𝑡ℎ
𝑅𝑎 ≤
𝑅𝑛
Ω
𝑀𝑎 ≤
𝑀𝑛
Ω
Untuk ASD, hubungan antara load dan strength:
This approach is called allowable stress design. The allowable stress will be in the elastic range of material.
It is also called Elastic Design or working stress design. Working stresses are those resulting from working loads,
which are applied loads. Working load = service load.
𝑃𝑎 ≤
𝑃𝑛
Ω

3. Struktur baja 1.3 Prinsip Desain
01
2. LRFD (Load and Resistance Factor Design)
LRFD = plastic design sehingga berlaku kriteria:
Untuk LRFD, hubungan antara load dan strength:
𝑅𝑢 ≤ ∅𝑅𝑛
Σ𝛾𝑖𝑄𝑖 = ∅𝑅𝑛

4. Struktur baja 1.3 Prinsip Desain
01
3. Safety Factors and Load Combinations for ASD
Ra is the sum of the service loads or load effects
Load combination for ASD given in ASCE 7. : 𝑅𝑎 ≤
𝑅𝑛
Ω

5. Struktur baja 1.3 Prinsip Desain
01
3. Safety Factors and Load Combinations for ASD

6. Struktur baja 1.3 Prinsip Desain
01
4. Load Factors, Resistance Factors, and Load Combinations for LRFD
𝑅𝑢 ≤ ∅𝑅𝑛
Σ𝛾𝑖𝑄𝑖 = ∅𝑅𝑛
Ra = required strength=sum of factored load effects
(moments or forces):
Design strength

7. Struktur baja 1.3 Prinsip Desain
01
1 Kips = 4.4482 Kilonewtons.

8. Struktur baja 1.3 Prinsip Desain
01
1 Kips = 4.4482 Kilonewtons.

9. Struktur baja 1.3 Prinsip Desain
01
1 Kips = 4.4482 Kilonewtons.

10. Struktur baja 1.3 Prinsip Desain
01
1 Kips = 4.4482 Kilonewtons.

11. Struktur baja 1.3 Prinsip Desain
01
1 Kips = 4.4482 Kilonewtons.
Tugas 1

12. Strength = the capacity of object to withstand force or pressure
Required Strength = maximum internal forces in a member establishes a minimum strength or capacity
that member must have in order to safely withstand the forces, the stresses and the
deformation that a member is experiencing
>> Demand of the forces is being produced in a structural element, however the
required itself varies depending on which design philosophy is being use.
Allowable and Design Strength = Available strength
= function of nominal strength and reduction factor