Pengaruh Parameter CNC Laser CO2 terhadap Akurasi dan Lebar Kerf pada Material Acrylic Composite dengan Finite Element Method

ZHAFRAN TAKAHASHI ADITAMA, Dr. Ir. Benidiktus Tulung Prayoga, S.T., M.T.; Dr. Handoko, S.T., M.T.; I. Aris Hendaryanto, S.T., M.Eng.

2025 | Tugas Akhir | D4 TEKNOLOGI REKAYASA MESIN

Laser cutting CNC CO₂ penting di manufaktur modern namun akurasi potongannya dipengaruhi parameter seperti daya laser, kecepatan, ketebalan material, dan posisi fokus. Ketidakakuratan menyebabkan pemborosan material, khususnya pada clear acrylic. Penelitian ini bertujuan mencari pengaturan optimal (daya, kecepatan, ketebalan) untuk meminimalkan surface roughness dan lebar kerf, serta membandingkan error antara uji makroskopik dan simulasi FEM guna memvalidasi akurasi simulasi.Penelitian menggunakan pendekatan hybrid simulasi FEM (ANSYS) dan eksperimen.

Parameter uji (speed, power laser, ketebalan material) dioptimasi via desain eksperimen Taguchi L9 dan ANOVA. Simulasi memodelkan distribusi panas (Gaussian moving heat source) dan efek termal pada akrilik. Validasi dilakukan dengan membandingkan lebar kerf dan kekasaran permukaan (roughness) hasil simulasi dengan uji makroskopik pada sampel potongan.

Optimasi parameter menggunakan SN ratio menunjukkan, Roughness minimum (Power 55W, speed 6mm/s, tebal 2mm) dipengaruhi signifikan oleh ketebalan material. Lebar kerf minimum (Power 55W, speed 4mm/s, tebal 5mm).Validasi simulasi memprediksi lebar kerf 787 ?m dengan error dibawah 10%. Berdasarkan hasil simulasi dengan parameter sebelumnya yang menghasilkan reliabel (error di bawah 10%). Parameter optimal berbeda untuk roughness (speed 6mm/s, daya 55W, tebal 2mm) dan kerf (speed 4mm/s, daya 55W, tebal 5mm). Namun pada kombinasi data X7 speed tinggi (8mm/s) dan daya rendah (55W) gagal memotong material tebal 5 mm.

CNC laser CO₂ cutting is important in modern manufacturing but its cutting accuracy is affected by parameters such as laser power, speed, material thickness, and focus position. Inaccuracies cause material wastage, especially in clear acrylic. This study aims to find the optimal settings (power, speed, thickness) to minimize surface roughness and kerf width, and compare the error between macroscopic test and FEM simulation to validate the accuracy of the simulation.The study uses a hybrid approach of FEM simulation (ANSYS) and experiment.

The test parameters (speed, laser power, material thickness) were optimized via Taguchi L9 experimental design and ANOVA. The simulation models the heat distribution (Gaussian moving heat source) and thermal effects on acrylic. Validation is done by comparing the simulated kerf width and surface roughness with macroscopic tests on cut samples.

Parameter optimization using SN Ratio shows: Minimum roughness (55 W, speed 6 mm/s, thickness 2 mm) is significantly affected by material thickness. Minimum kerf width (Power 55 W, speed 4 mm/s, thickness 5 mm). Simulation validation predicts a kerf width of 787 ?m with an error under 10%. Based on the results of Simulation with previous parameters that produce reliable (error below 10%). Optimal parameters are different for roughness (speed 6 mm/s, power 55 W, thickness 2 mm) and kerf (speed 4 mm/s, power 55 W, thickness 5 mm). However, in the X7 data combination high speed (8 mm/s) and low power (55 W) failed to cut the 5 mm thick material.

Kata Kunci : Laser Process, FEM (Finite Element Method), Acrylic PMMA (Polymethyl methacrylate), Composite, Moving Heat Source, Kerf, Roughness Surface, Taguchi Method.