Kerusakan adalah hal yang tentunya akan dialami oleh struktur. Untuk mengkuantifikasi hal tersebut, digunakan konsep yang dinamakan damage index. Damage index adalah sebuah indeks nilai yang mengkuantifikasi kerusakan dari sebuah sistem struktur dengan menggunakan parameter seperti kekuatan struktur, displacement dan sebagainya. Selain dari itu, kerusakan struktur juga mempengaruhi nilai kekakuan struktur sehingga akan berpengaruh pula pada frekuensi natural struktur.
Penelitian ini ingin menganalisis korelasi antara damage index dengan frekuensi natural sebuah struktur seiring kerusakan yang dialami. Untuk mencapai tujuan tersebut, dilakukan studi parametrik dengan membuat kurva kapasitas pushover (monotonic dan semicyclic) dari struktur menggunakan CAST3M untuk mendapatkan nilai damage index. Lalu frekuensi natural struktur didapatkan dengan menggunakan SAP2000. Studi parametrik dibuat dengan variasi geometri penampang, jumlah bay dan story, dan variasi properti material yang digunakan.
Dari hasil penelitian didapatkan bahwa seiring struktur mengalami kerusakan, damage index cenderung mengalami peningkatan dan frekuensi alami mengalami penurunan.
Indonesia is an archipelago that is often plagued by earthquakes. And so, the need for structure that can handle lateral loads is important. One of the candidates for the lateral load-resisting structure type is Ordinary Momen Frame (OMF). This research focuses on the aforementioned lateral load-resisting structure type using reinforced concrete as choice material.
Damage is a natural phenomenon that will happen to structures. To quantify it, concept called damage index is used. Damage index itself is an index that make use of parameter such as structural strength, displacement and so forth. Besides damage index, damage to structure will also influence its natural frequency.
This research aims to analyze the correlation between damage index and natural frequency of structures as it get progressively damaged. To do so, a parametric study is carried out by creating pushover capacity curves (monotonic and semicyclic) of the structures using CAST3M to obtain the damage index value. Following that, natural frequency of the structures are generated using SAP2000. The parametric study will be realized through the variations of cross-section geometry, number of bay and story, and variation in material property used.
From the research, it is concluded that as the structures get progressively damaged, the value of the damage index tends to increase while the natural frequency decrease.
Penelitian ini membahas hubungan cepat rambat gelombang ultrasonik dengan kuat tekan dan pola retak beton daur ulang. Pengujian cepat rambat gelombang ultrasonik (UPV) dilakukan menggunakan PUNDIT. Pengamatan pola retak menggunakan metode digital image correlation (DIC). Benda uji yang dibuat adalah 16 kubus ukuran 15 cm dan 4 balok ukuran 15x15x50 cm. Spesimen kubus diuji tekan di umur 3, 7, 14, dan 28 hari dan di umur 28 disertai metode DIC. Pengujian metode DIC menggunakan kamera Fuji Film XA-3 dan diolah dengan software Ncorr pada MATLAB. Benda uji balok diuji UPV setiap jamnya di 24 jam pertama dan setiap hari sampai umur 28 hari. Penelitian ini menghasilkan hubungan logaritmik antara nilai UPV dan umur beton daur ulang dengan persamaan tiap benda uji sebagai berikut, VA = 2.68745E+02ln(x)+1.92197E+03, R2=0.809, VB = 2.75780E+02ln(x) + 1.82082E+03, VC = 3.51058E+02ln(x) + 1.59413E+03, dan VD = 3.51448E+02ln(x) + 1.61130E+03 dengan nilai R2 sebagai berikut, RA 2 =0.809, RB 2=0.844, RC 2=0.762, dan RD 2=0.772. Dihasilkan hubungan eksponensial antara kuat tekan beton dan nilai UPV dengan persamaan fc = 1.58593E01e1.22057E+00V[m/s] dengan nilai R2=7.36785E-01. Hasil pengujian metode DIC menunjukkan evolusi deformasi vertikal dan horizontal serta evolusi pola retak dari beton daur ulang. Stiffness tiap benda uji sebesar B = 862.92 kN/mm, C = 902.21 kN/mm, dan D = 1018.22 kN/mm. Poisson ratio dari benda uji sebesar B = 0.2478, C = 0.2302, dan D = 0.2392.
This research will conduct a discussion about relationship between ultrasonic pulse velocity and compressive strength along with crack pattern of recycled concrete. Ultrasonic pulse velocity (UPV) will be measured using the PUNDIT. Observation of crack patterns using digital image correlation (DIC) method of recycled concrete. The specimens to be made are 16 cubes with dimension of 15cm and 4 beam with dimension of 15x15x50 cm. Cube specimens aged 3, 7, 14, and 28 days will be tested and on the day 28 will use DIC method. DIC method use Fuji Film XA-3 as to capture pictures which will be processed with Ncorr on MATLAB. Beam specimens will be used for UPV test within every hour in the first 24 hours and every day up to 28 days. This study results show logarithmic relationship between the UPV and the age of recycled concrete with the result equation each specimen as follows, VA = 2.68745E + 02ln (x) + 1.92197E + 03, VB = 2.75780E + 02ln (x ) + 1.82082E + 03, VC = 3.51058E + 02ln (x) + 1.59413E + 03, and VD = 3.51448E + 02ln (x) + 1.61130E + 03 with the coefficient of determination of each specimen as follows, RA2 = 0.809, RB2 = 0.844, RC2 = 0.762, and RD2 = 0.772. Exponential relationships shown between concrete compressive strength and UPV in equation of fc = 1.58593E01e1.22057E + 00V [m / s] with R2 = 7.36785E-01. The DIC test results show the evolution of vertical and horizontal deformations as well as the evolution of crack patterns of recycled concrete. Stiffness of each specimens as follows, B = 862.92 kN / mm, C = 902.21 kN / mm, and D = 1018.22 kN / mm. Poisson ratio of each specimens as follows B = 0.2478, C = 0.2302, and D = 0.2392.