Structural Damage Detection of A Steel-Truss Railway Bridge Using its Dynamic Characteristics

Many steel truss rail bridges in Indonesia were built decades ago. To assure that bridge structure is in-service conditions, periodic monitoring is required, thus structural health of the bridge can be assessed and sudden collapse of the structure can be avoided. In health monitoring of structure, structural damage detection methods are frequently required so that damaged/weak element of the structure can be identified and technique for repairing it can be determined. In this paper, structural damage detection method of steel truss bridge is discussed. The method applied in this study used vibration characteristics of the structure for detecting structural damages occurred in the structure. The method was utilized to identify simulated damages occurred in a steel-truss railway bridge located in Porong East Java. The bridge has span of 30 meters and it was built during the era of Dutch colonization. The structure was modeled numerically utilizing CSI Bridge v15 computer software for facilitating in obtaining its dynamic characteristics. Results of this study showed that the method could identify precisely the existence of damage took place in the structure.

Sandwich Core Material Development for Ship Deck Structure

Development of sandwich materials for ship structure is aimed mainly to reduce the ship light weight so that the ship payload increases. This paper addresses development of sandwich core material suitable for ship structure. The core materials were composed of synthetic resin and talc; percentages of talc by total weight investigated were 10%, 20%, 30%, and 40%. Laboratory tests stipulated by the Lloyd’s Register (LR) and Det Norske Veritas (DNV) were performed on the core materials. Moreover, sandwich plates consisted of steel faceplates and the core materials were tested using ASTM standards including tension, shear, and flexure tests. The sandwich plates were applied for designing car deck of a ro-ro ship. Analysis of the sandwich deck under design load utilizing finite element approach was carried out to select the best sandwich core materials developed in this study. It was observed that the sandwich panel deck composed of synthetic resin and core material with 40% talc was better than the others

Aplikasi Sandwich Plate System Berbahan Core Limbah Cangkang Kerang pada Geladak Kapal

The development of technology in the field of materials and construction produces many innovations, one of them is sandwich plate system. Sandwich plate system is a material formed by two different materials into one layer. Sandwich plate system consists of face that from plate and core form composite. Clam shells are one of the waste materials that can be used as filler on the core. The composite material that use as a core is a mixture of clam shells powder as filler and resin as a matrix. The combination of clam shells powder and resin, produces strong composite materials. Sandwich plate system using core from clam shelsl powder and resin produce good strength. The material using 20% clam shells powder as filler of the resin weight has maximum stress 53.32 N/mm2 on the deck and 53.20 N/mm2 for 30% of filler by weight of the resin. The maximum stress value is still below the permission stress required by the class rule

Study on local scouring at Suramadu bridge piers for structural integrity monitoring

Local scour at bridge piers needs to be monitored regularly when the bridge is in-service since it may affect the integrity of the bridge structure and occasionally it can lead to a catastrophe. Scour at bridge piers varies with water depth, flow velocity and duration, pier geometry, and other factors. This paper discusses results of local scour study at piers of Suramadu Bridge, which is at present the longest bridge in Indonesia, for monitoring of its integrity. Field investigations were carried out to obtain sea water current speed and direction, the sea bottom profile, and seabed soil size distribution. Areas at the vicinity of the bridge piers where scouring and sedimentation took place were obtained by comparing results of this study to those of similar study reported earlier. In addition to field investigations, numerical investigation was also conducted in this study to estimate local scour depths occurred at piers of the bridge. Scour depths obtained from the measurements in the field and those numerically computed were compared. Effect of estimated scouring on the bearing capacity of the bridge pier foundation was then investigated. Results of the study showed that the integrity of Suramadu bridge structure was not affected under the estimated scour depth; however, monitoring of the bridge structure requires to be conducted regularly so that its structural integrity can be assured

Analisis Strategi Pengadaan Palm Kernel Expeller pada PT X

This research is based on case study aims to identify ongoing PKE procurement strategy in PT X, to capture the problem along with its cause and the impact itself for the company. This research also tries to develop the more relevant procurement strategy to company's necessity. The method in this research is qualitative descriptive through data analysis derived from in depth interview, field observation, also documentation. Current PKE procurement strategy in PT X still not able to accommodate customer's need hence cause losses due to instability quantity amount of supply. Procurement strategy development by creating consolidation warehouse aims to mitigate the problem risk in PKE procurement with its cost consideration

Sandwich Panel Manufacturing Method in Form of Test Specimens for Ship Construction

Sandwich panel as a composite materials require special method of manufacture, to produce the best of physical condition. This study give the manufacturing process of sandwich panel for the purpose of testing the strength of material. Sandwich panel created with molding method for simplify the process of work and can be repeated if a failure occurs. Saveral failures occur in creating process until preparation specimen process that are influenced by saveral things, such as damage caused by the temperature of the sun, difference in viscosity between the layers of the conditions faceplate (smooth and rough), and the method of cutting the sandwich panel which requires cutting methods at low temperatures and does not produce the high vibration to avoid damage to the material before material strength test were performed

OMAE2004-51109 CRACK IDENTIFICATION ON A CROSS-STIFFENED PLATE PANEL

ABSTRACT Early identification of cracks in complex structures is desirable for the safety of operation and economy of maintenance of the structure. Monitoring of the vibration response of structures is a well-known technique for crack identification. As the complexity of the structure increases manual inspection becomes difficult and the use of on-line monitoring techniques for crack detection becomes more desirable. This paper discusses the use of a structure's vibration response in the early detection of cracks. Analytical and experimental studies of the effect of cracks on the vibration response of an 1/20 scale aluminum model of the stiffened side shell panel of a tanker were carried out. The model was carefully designed to obtain natural frequencies and mode shapes similar to those of the prototype structure. The results of the analytical study were used to determine the best locations to place the sensors on the experimental model. Results of the experimental and analytical studies are reported