Journal of Applied Mechanical Technology

Effect of Insulation on the Resistance Spot Welds with an Electrode Parallel Gap Single-Sided Double Spot

2024-06-06T03:43:51+00:00

Current leakage in parallel gap single-sided double spot welding tools occurs if the insulation to the mass-body, either from the work table or the drive system, can reduce the current concentration and result in double-sided welding being relatively difficult to carry out or the weld results being poor. Therefore in this research, an experiment was carried out to test the machine how big the effect of leakage current is on the quality of welded joints by comparing the strength of the joint between a system without insulation and a system using insulation using the independent sample t-test statistical method with a confidence level of 95%. The results of the study show that overall the max load for CT 3 to 10 is a mean difference between without and with insulation, although it is not very significant, this is because the shear test data from the group without insulation has quite a high deviation. High deviations also occur in the upper yield data, the strongest conclusion is that providing insulation (or preventing leakage current) provides a more consistent welding result as seen from the results of the shear test data. Only CT 3 has a significant impact on both max load and upper yield.

Studi Kasus Penjadwalan Proyek: Frame Acid Skid dengan Gant Chart dan Critical Path Method

2024-06-20T06:55:47+00:00

This study examines the scheduling of the Frame Acid Skid project at the Lombok Steam Power Plant (PLTU) using Gantt Chart and Critical Path Method (CPM). The primary objective is to identify the causes of delays and propose optimization measures for the project duration. Data collected indicates a significant difference between the planned duration (24 days) and the actual project completion time (47 days). The main delays occurred in the welding and painting phases, each requiring an additional 13 days. Contributing factors include the addition of a welding process for materials not covered in the initial contract and specification mismatches in the painting phase. Analysis with Gantt Chart and CPM reveals that enhanced communication, more detailed initial planning, and strict monitoring of project specifications are crucial to minimize the impact of delays on cost and time. The results of this study provide a strong basis for decision-making in similar future projects.

Rancang Bangun Mesin Hot Press Particle Board Sekam Padi Berbasis Pneumatik

2024-05-30T01:39:15+00:00

Rice husk waste, often produced by the rice milling industry, creates a problem. To utilize rice husk waste, one of the uses is to make a product in the form of particle board by heating and pressing with a hot press machine. This study aims to design and build a hot press machine to make a rice husk particle board with a press using a pneumatic system. The method for making a hot press machine is by making a machine design, load calculations, and static simulations on the frame, then manufacturing using a fabrication and assembly process. The results of the design and manufacture were obtained with machine dimensions of 1372x800x700mm, maximum heating temperature of 175oC, a pneumatic system using two double-acting actuators, von Misses stress results from an even load of 143 N on the frame, obtained a von Misses stress of at least 2.405e-1N/m2 and The maximum Von Misses Stress of 1.856e6N/m2is still a safe limit because above the yield strength value of the material used, the maximum displacement value is 1.098 mm. The safety factor is 2.01.

Pengaruh Perbandingan Fraksi Volume Serat Eceng Gondok Dan Serat Sabut Kelapa Terhadap Kekuatan Tarik Bermatrik Resin Epoxy

2024-05-21T05:33:52+00:00

The purpose of using natural fibers as reinforcement for composite materials is expected to be an alternative material to replace the used of fiberglass fibers and is expected to be able to increase the quality of water hyacinth fibers and coconut coir fibers. In this study, to determine the best tensile strength value, several experiments were carried out using the determine factor of the fiber volume fraction of 20%, 25%, 30% and the immersion factor with NaOH solution for 4 and 6 hours using a matrix in the form of epoxy resin. The test results showed that the variation of soaking in alkaline solution media (NaOH) for 6 hours with a volume fraction of 30% obtained the best tensile strength results with each type of fiber, water hyacinth fiber obtained the best results of 23.32 MPa while coco fiber the best result was 22.10 MPa.