tugas ads contoh perhitungan modal 2

CONTOH  SOAL 1 :

H =   3  meter

L  =   3  meter

 

PENYELESAIAN:

Ø  Input data

·         BARIS 1

5              =  Zona gempa

1              =  Tanah keras

981         =  Tingkat gravitasi

0.04        =  Skala gempa

1              =  I.K

3              = Bayak tingkat

3              = Ragam Getar

0.05        = Faktor redaman

·         Kolom 1

W = q x l

Dari nilai W 

W 1=  3 x 6                                                          

        = 18 ton = 18000 kg

W 1=W2=W3

·         KOLOM2

KEKAKUAN TINGKAT

K1 = 12x2,3x10^{5 .} X b x h³

                                      H³

      = 12x2,3x10^{5 .} X 50⁴

                                          400³

         = 22461 kg/cm  ( 3 kolom )

K2= K3=K1

·         KOLOM 3

H1 = 400 cm

H2= 400  +  400

     =800 cm

H3= 800 + 400

     = 1200 cm

H4 =1200 + 400

      = 1600 cm

H5= 1600 + 400

      = 20000 cm

1.       PERIODE GETAR ALAMI

a.    Mode I =  T₁ = 0,40 detik

b.    Mode II = T₂ = 0,14 detik

c.     Mode II = T₃ = 0,09 detik

2.       POLA RAGAM GETAR

1.       DISTRIBUSI GAYA GESER GEMPA

SDOF

Single Degree of Freedom

Definition

The simplest vibratory system can be described by a single mass connected to a spring (and possibly a dashpot). The mass is allowed to travel only along the spring elongation direction. Such systems are called Single Degree-of-Freedom (SDOF) systems and are shown in the following figure,

Equation of Motion for SDOF Systems
SDOF vibration can be analyzed by Newton's second law of motion, F = m*a. The analysis can be easily visualized with the aid of a free body diagram, The resulting equation of motion is a second order, non-homogeneous, ordinary differential equation:  with the initial conditions,  The solution to the general SDOF equation of motion is shown in the damped SDOF discussion.