Tatacipta Dirgantara, Tatacipta
Lightweight Structures Research Group, Aeronautics & Astronautics Department Faculty of Mechanical and Aerospace Engineering, Institut Teknologi Bandung

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Journal : Journal of Engineering and Technological Sciences

Head Injury Analysis of Vehicle Occupant in Frontal Crash Simulation: Case Study of ITB’s Formula SAE Race Car Mihradi, Sandro; Golfianto, Hari; Mahyuddin, Andi Isra; Dirgantara, Tatacipta
Journal of Engineering and Technological Sciences Vol 49, No 4 (2017)
Publisher : ITB Journal Publisher, LPPM ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (482.958 KB) | DOI: 10.5614/j.eng.technol.sci.2017.49.4.8

Abstract

In the present study, frontal crash simulations were conducted to determine the effect of various car speeds against the Head Injury Criterion (HIC), a measure of the likelihood of head injury arising from impact. The frontal impact safety of ITB’s formula SAE race car designed by students was evaluated as a case study. LS-DYNA®, an explicit finite element code for non-linear dynamic analysis was utilized in the analysis. To analyze head injury, a two-step simulation was conducted. In the first step, a full-frontal barrier test was simulated without incorporating a dummy inside the car. The output was the deceleration data of the car, which was used as input in the second step, a sled test simulation. In the sled test, only the cockpit and dummy were modeled. The effect of deceleration to the head of the dummy was then evaluated. The results show that HIC values at an impact speed of 7 m/s (25 km/h) to 11 m/s (40 km/h) were below the safe limit and still in the safe zone. However, the HIC values will exceed the safe limit when the speed of impact is the same as or greater than 12 m/s (43 km/h).
Head Injury Analysis of Vehicle Occupant in Frontal Crash Simulation: Case Study of ITB’s Formula SAE Race Car Sandro Mihradi; Hari Golfianto; Andi Isra Mahyuddin; Tatacipta Dirgantara
Journal of Engineering and Technological Sciences Vol. 49 No. 4 (2017)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2017.49.4.8

Abstract

In the present study, frontal crash simulations were conducted to determine the effect of various car speeds against the Head Injury Criterion (HIC), a measure of the likelihood of head injury arising from impact. The frontal impact safety of ITB's formula SAE race car designed by students was evaluated as a case study. LS-DYNA®, an explicit finite element code for non-linear dynamic analysis was utilized in the analysis. To analyze head injury, a two-step simulation was conducted. In the first step, a full-frontal barrier test was simulated without incorporating a dummy inside the car. The output was the deceleration data of the car, which was used as input in the second step, a sled test simulation. In the sled test, only the cockpit and dummy were modeled. The effect of deceleration to the head of the dummy was then evaluated. The results show that HIC values at an impact speed of 7 m/s (25 km/h) to 11 m/s (40 km/h) were below the safe limit and still in the safe zone. However, the HIC values will exceed the safe limit when the speed of impact is the same as or greater than 12 m/s (43 km/h).
Numerical Simulation of Damage in Sandwich Composite Panels Due to Hydrodynamic Impact Satrio Wicaksono; Nur Ridhwan Muharram; Hermawan Judawisastra; Tatacipta Dirgantara
Journal of Engineering and Technological Sciences Vol. 53 No. 3 (2021)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2021.53.3.4

Abstract

The float and hull are vital parts of amphibious planes and boats, respectively, as both have to absorb hydrodynamic impact due to interaction with water. Sandwich composite panels are commonly used for such applications and other impact-absorbing structures. Unfortunately, the failure mechanism of sandwich composite panels under hydrodynamic impact is very complicated, as it may consist of composite skin failure, core failure, and non-uniform delamination. Hence, a numerical study on the damage of sandwich composite panels under hydrodynamic load is necessary. In this study, numerical simulation implementing the Coupled Eulerian-Lagrangian (CEL) method was performed to observe the damage mechanism of sandwich composite panels. The CEL method combines the Lagrangian and Eulerian frames into one model. Thus, analysis of structure deformation and fluid motion can be performed simultaneously. The result of the current numerical simulation shows a fair agreement with the experimental results in the literature, which shows that the current methodology can represent the sandwich composite panel response in real-life conditions, especially before shear core failure initiates.
Development of Laboratory-scale Lamb Wave-based Health Monitoring System for Laminated Composites Leonardo Gunawan; Muhammad Hamzah Farrasamulya; Andi Kuswoyo; Tatacipta Dirgantara
Journal of Engineering and Technological Sciences Vol. 53 No. 4 (2021)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2021.53.4.7

Abstract

This paper presents the development process of a laboratory-scale Lamb wave-based structural health monitoring (SHM) system for laminated composite plates. Piezoelectric patches are used in pairs as actuator/sensor to evaluate the time of flight (TOF), i.e. the time difference between the transmitted/received signals of a damaged plate and those of a healthy plate. The damage detection scheme is enabled by means of evaluating the TOF from at least three actuator/receiver pairs. In this work, experiments were performed on two GFRP plates, one healthy and the other one with artificial delamination. Nine piezoelectric transducers were mounted on each plate and the detection of the delamination location was demonstrated, using 4 pairs and 20 pairs of actuators/sensors. The combinations of fewer and more actuators/sensor pairs both provided a damage location that was in good agreement with the artificial damage location. The developed SHM system using simple and affordable equipment is suitable for supporting fundamental studies on damage detection, such as the development of an algorithm for location detection using the optimum number of actuator/sensor pairs.
Lessons Learned from Rapid Development of CPAP Ventilator Vent-I during Covid-19 Pandemic in Indonesia Syarif Hidayat; Jam'ah Halid; Tatacipta Dirgantara; Mipi Ananta Kusuma; Hari Utomo; Reza Widianto Sudjud; Ike Sri Rejeki; Sandro Mihradi; Sri Raharno; Dadang Rukanta; Hari Tjahjono
Journal of Engineering and Technological Sciences Vol. 52 No. 5 (2020)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2020.52.5.11

Abstract

Here, lessons learned during the development of the CPAP ventilator 'Vent-I', aimed to help COVID-19 patients with breathing difficulties, are presented. Within only weeks, the Vent-I was developed, complying with functionality, safety and reliability requirements and passing the clinical trial. It was then distributed to hospitals all over Indonesia. Two billion rupiahs were raised through crowdfunding within one week. When the project was officially closed, more than one thousand Vent-I devices had been distributed and more than twelve and a half billion rupiahs had been raised. Currently, commercialization and mass production of the device have been started. From this project several lessons can be learned. First and foremost, the spirit of gotong royong"“ sincere collaboration within the community to help each other "“ is still firmly rooted within the people and the society of Indonesia. Noble values, i.e. sincerity, sensitivity and concern about the needs of the community, willingness to serve voluntarily and public trust, made the team dare to try and face failure. The spirit of social entrepreneurship, willingness to listen to the user and collaboration with the relevant authority can accelerate development process. The availability of knowledge and skills that constitute an innovation ecosystem in Bandung, supported by business, social institutions and government, was also a key success factor..
Experimental Work for Bar Straightness Effect Evaluation of Split Hopkinson Pressure Bar Afdhal Afdhal; Leonardo Gunawan; Tatacipta Dirgantara
Journal of Engineering and Technological Sciences Vol. 53 No. 6 (2021)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2021.53.6.13

Abstract

Bar straightness is one of several factors that can affect the quality of the strain wave signal in a Split Hopkinson Pressure Bar (SHPB). Recently, it was found that the bar components of the SHPB at the Lightweight Structures Laboratory displayed a deviation in straightness because of manufacturing limitations. An evaluation was needed to determine whether the strain wave signals produced from this SHPB are acceptable or not. A numerical model was developed to investigate this effect. In this paper, experimental work was performed to evaluate the quality of the signal in the SHPB and to validate the numerical model. Good agreement between the experimental results and the numerical results was obtained for the strain rates and stress-strain relationship for mild steel ST37 and aluminum 6061 specimen materials. The recommended bar straightness tolerance is proposed as 0.36 mm per 100 mm.