Analisis Gaya Longitudinal pada Coupler Draft Gear Gerbong Datar Batu Bara 54 ton di Lintas Niru-Prabumulih Berbasis Multibody Dynamics Simulation
Arohman Bagas Saputra, Dr. Ir. Eng. Agustinus Winarno, S.T., M.Eng
2026 | Tugas Akhir | D4 TEKNOLOGI REKAYASA MESIN
Kereta api merupakan moda utama
distribusi batu bara di Sumatera Selatan, khususnya pada lintas
Niru-Prabumulih, dengan kapasitas angkut gerbong datar mencapai 54 ton per
unit. Peningkatan tonase berpotensi meningkatkan gaya longitudinal pada
sistem coupler draft gear, sehingga diperlukan analisis karakteristik
dinamisnya. Penelitian ini menganalisis gaya longitudinal pada sistem coupler
draft gear gerbong datar batu bara 54 ton di lintas Niru-Prabumulih
menggunakan simulasi Multibody Dynamics berbasis Universal Mechanism.
Pemodelan dilakukan pada rangkaian
dua gerbong dengan kondisi unload (14,872 ton) dan maxload (54
ton), serta variasi kecepatan dan geometri lintasan. Parameter draft gear
dikonstruksi berdasarkan spesifikasi teknis friction draft gear gerbong
barang dengan kurva force-displacement tiga zona: soft region
(0–35 mm), progressive region (35–74 mm), dan hardening region
(74–83 mm), dengan impedance force 2.270 kN, kapasitas energi ? 50 kJ,
dan absorbing ratio 80%.
Variasi beban berpengaruh
signifikan, dengan gaya terbesar meningkat dari 35.305 N (unload)
menjadi 126.826 N (maxload), jauh di bawah batas impedance force
2.270 kN. Gaya buff konsisten lebih besar dari gaya draft akibat
efek slack action dan gaya inersia pada fase pengereman. Variasi
kecepatan (20–70 km/jam) berpengaruh terhadap gaya longitudinal, namun
percepatan terbukti sebagai parameter dominan variasi kecepatan dengan profil
percepatan konstan menghasilkan gaya hampir identik (126,15–127,38 kN). Variasi
geometri lintasan tidak berpengaruh secara signifikan karena gaya sentripetal
bekerja pada arah lateral.
Railways are
the primary mode of coal distribution in South Sumatra, particularly on the
Niru-Prabumulih route, with flatbed wagons carrying loads of up to 54 tons per
unit. The increase in freight tonnage potentially amplifies longitudinal forces
within the coupler draft gear system, necessitating analysis of its dynamic
characteristics. This study analyzes the longitudinal forces acting on the
coupler draft gear of a 54-ton coal flatbed wagon on the Niru-Prabumulih route
using Multibody Dynamics simulation through Universal Mechanism software.
The model
consists of a two-wagon consist under unloaded (14.872 tons) and maximum load
(54 tons) conditions, with variations in operating speed and track geometry.
Draft gear parameters were constructed based on the technical specifications of
a friction draft gear for freight wagons, incorporating a force–displacement
curve with three characteristic zones: soft region (0–35 mm), progressive
region (35–74 mm), and hardening region (74–83 mm), with an impedance force of
2,270 kN, energy capacity ? 50 kJ, and an absorbing ratio of 80%.
Load
variation significantly affects longitudinal force, with the largest force
increasing from 35,305 N (unloaded) to 126,826 N (maximum load) in the buff
direction, remaining well below the 2,270 kN impedance force limit. Buff forces
consistently exceed draft forces due to slack action effects and inertial
forces during braking. Speed variation (20–70 km/h) affects longitudinal force,
however acceleration is confirmed as the dominant parameter speed variation
under a constant acceleration profile yields nearly identical forces
(126.15–127.38 kN). Track geometry variation does not significantly affect
longitudinal forces as centripetal forces act in the lateral direction.
Kata Kunci : Coupler Draft Gear, Longitudinal Force, Multibody Dynamics, Railway Vehicle Dynamics
