http://repository.president.ac.id/xmlui/handle/123456789/3264 2026-06-13T15:26:58Z 2026-06-13T15:26:58Z Anggraini, Lydia Hernawan, Rendi http://repository.president.ac.id/xmlui/handle/123456789/13884 2026-05-07T05:54:04Z 2025-01-01T00:00:00Z

DEVELOPMENT AND VALIDATION OF THERMOCOUPLE FOR THERMODYNAMICS EXPERIMENT Anggraini, Lydia; Hernawan, Rendi Undergraduate students often struggle with Thermodynamics due to a lack of hands-on experience with the devices and sensors discussed in coursework. Traditional experimental setups—such as engine test benches and HVAC systems—are prohibitively expensive and maintenance-intensive, limiting student access and requiring large group work that can reduce individual engagement. To address this issue, we developed and implemented a costeffective thermocouple calibration apparatus for use in undergraduate Thermodynamics laboratories. The equipment utilizes affordable, readily available components, enabling the creation of multiple identical setups within a constrained budget. This allows students to work in smaller groups, increasing interaction and individual learning opportunities. The apparatus supports instruction in key Thermodynamics concepts, including temperature measurement, sensible and latent heat, and the Seebeck effect. Results from implementation show improved student comprehension and engagement. This approach offers a scalable, practical solution for enhancing Thermodynamics education, with potential applications across engineering curricula seeking to improve experiential learning within limited resources.

2025-01-01T00:00:00Z Anggraini, Lydia http://repository.president.ac.id/xmlui/handle/123456789/13880 2026-05-05T07:15:57Z 2026-01-01T00:00:00Z

THE EFFECT OF POST WELD HEAT TREATMENT AND ITS EFFICIENCY ON THE AXLE HOUSING OF 440 STEEL AUTOMOTIVE PRESS HOT Anggraini, Lydia This study discusses the effect of Post Weld Heat Treatment (PWHT) and welding efficiency on the axle housing of Steel Automotive Press Hot (SAPH) 440, where the axle housing is a critical component in automotive vehicles. The research was conducted using the Double-Electrode Gas Metal Arc Welding (DE-GMAW) method for welding efficiency, with butt joints. Macroand micro-structure tests, as well as hardness tests using the Vickers Test, were also performed. These tests aim to provide insights into welding quality, defects, and the effect of PWHT on SAPH 440. From the results, the ideal welding parameters for Axle Housing welding are 300 A current, 29 V voltage, 140 cm/min welding speed, and 110 cm/min filler wire speed. Macrostructure testing shows that the obtained sizes exceed the standard, and using the DEGMAW allows axle housing welding to be performed faster than conventional methods. Microstructure testing shows a difference between non-PWHT with ferrite grains of ±5-10 μm and with-PWHT specimens with larger and coarser grains of approximately ±25 μm, due to grain growth. Micro Vickers testing shows that the non-PWHT has a higher hardness value in the heat-affected zone (HAZ) area, around 176.28 HV, while the with-PWHT specimens have a lower hardness value in the HAZ area, around 150.64 HV. However, the with-PWHT is much tougher, proving that grain growth and reduced internal stress have occurred. The selection of SAPH 440, solid wire as filler, and the use of MAG gas are a suitable combination for axle housing welding.

2026-01-01T00:00:00Z Sudania, Muhammad Anggraini, Lydia Hussain, Waqar http://repository.president.ac.id/xmlui/handle/123456789/13871 2026-05-05T04:53:35Z 2025-01-01T00:00:00Z

NON-DESTRUCTIVE TESTING OF HYDRAULIC CYLINDER EXCAVATOR BUCKET AND FAILURE ANALYSIS Sudania, Muhammad; Anggraini, Lydia; Hussain, Waqar The bucket cylinder is one of the important components in the front attachment of the excavator. The component is combined with a hose that flows the hydraulic oil flow from the hydraulic pump, and control valve to the bucket cylinder, which moves the bucket on the excavator. If the bucket cylinder does not work according to standards, a malfunction will occur which causes problems with the excavator so that damage occurs to the inner parts components. The research method used is an observation of the damaged bucket cylinder components, after observing the bucket cylinder check, interviewing the excavator operator, and checking using a dye penetrant, the bucket disassembly process is carried out to determine the condition of the bucket cylinder components to make it easier to observe the damage that occurs to the bucket cylinder, then the bucket cylinder component disassembly process is carried out then the inspection process is carried out using dye penetrant and hydraulic oil sampling to make it easier to collect data on the damage that occurs to the bucket cylinder components after the inspection of the damaged parts is carried out, repairs and replacement of spare parts with new ones so that the bucket cylinder can be reused.

2025-01-01T00:00:00Z Anggraini, Lydia Erwin Siahaan Lutfi Fadilah http://repository.president.ac.id/xmlui/handle/123456789/11753 2024-01-25T04:15:16Z 2021-01-01T00:00:00Z

Thin Plate Welding of Al 5083 Alloy by GMAW Applied for Electric Substations Equipment Anggraini, Lydia; Erwin Siahaan; Lutfi Fadilah In order to fill the manufacture demand of electric substation equipment, materials with the characteristics of rust-resistant, lightweight and easy to find are required. Aluminum 5083 alloy is the best candidate to use because one of advantages is excellent thermal conductivity. Gas Metal Arc Welding (GMAW) is used because it has high welding efficiency, it does not need to change welding wire frequently, can be used for all types of materials and welding positions, and does not produce scale or slag. The purpose of this research is to evaluate the GMAW welding parameters on the mechanical properties of Al 5083 alloy. The specimen of Al 5083 alloy is cut into V Groove with 30° or 60° angle each side, for 6 pieces with dimension of 300 mm length and 150 mm width, before welding process. The welding process is done using the manipulator machine with constant speed and various currents followed by mechanical testing. The mechanical testing results obtained, there is no significant difference on the tensile strength results of all specimens with different welding parameters. However, the elongation percentage result obtained, the highest strain is about 17% of the Al 5083 alloy thin plate specimen with 225 A current. It can be concluded that the Al 5083 alloy material through the GMAW process with appropriate has met the requirement of mechanical properties to be applied for the electric substation equipment. International Symposium on Advances in Mechanical Engineering 2021. p. 1-6.

2021-01-01T00:00:00Z