Desain dan Pabrikasi Helmet Industri yang Ergonomik

Abstract

Tesis ini melaporkan hasil desain dan pabrikasi model helm industri dari bahan komposit polimer GFRP tipe polyester (resin unsaturated), dengan serat E-Glass jenis Choped Strand Mat. Pada proses pabrikasi helm komposit ini, dengan susunan dua lapisan serat E-Glass jenis CSM, yang dibentuk mengikuti bentuk cetakan helm standard AS/NZS 1801 EN 397 SS 98 dengan metode hand lay up. Sistem pencetakan helmet dilakukan secara terpisah, dan empat sisi dinding helmet dibuat saluran angin. Hasil pengujian statik diperoleh tegangan maksimum ( max ) = 277 MPa, dan harga modulus elastisitasnya (E) = 782 MPa, menggunakan alat uji Ht-9502 Computer Hidrolic Universal Testing Machine. Pengujian ergonomik dilakukan dengan alat termokopel, hasil pengukuran temperatur udara di dalam dinding helm menunjukkan sebesar 33,160C, dan berat helm komposit setelah di produksi adalah 365 gram, menggunakan digital SAUTER D-7470. Untuk pengujian kekuatan helm dengan beban impak kecepatan tinggi menggunakan alat uji KOMPAK. Pengujian batang input dilakukan dengan teknik pengukuran dua gage, untuk mengetahui besar respon tegangan impak pada batang input dengan tekanan 0,4 MPa, pada jarak impak (ID): 60 mm: maka diperoleh respon tegangan (imp. ) = 362 MPa. Pengujian impak atas model helm TSA, pada (ID): 60 mm, dan SG.arah: X, diperoleh tegangan impak (imp. ) = 64,43 MPa, dan tegangan insiden (c ) = 24,50 MPa. Untuk pengujian kekuatan model helm [TSA], dengan impak atas, dan variasi jarak impak 40 mm s.d 120 mm, posisi SG. arah: X, diperoleh respon tegangan impak (imp ) = -10,96 MPa, dan untuk model helm DSA (imp ) = -21,61 MPa. Sedangkan untuk model helm TSA, dengan jarak impak 60 mm, posisi SG. arah: Y, diperoleh respon tegangan impak (imp ) = 67,77 MPa, dan tegangan insiden (c ) = 26,28 MPa. Begitu juga pada jarak impak 140 mm, diperoleh besar respon tegangan impak (imp ) = 91,89 MPa, dan tegangan insiden (c ) = 36,80 MPa. Untuk pengimpakan samping model helm [TSA] (imp ) = - 6,61 MPa, dan model helm [DSA] (imp ) = - 4,24 MPa. Selanjutnya meredesain model konstruksi helm komposit, untuk mengklarifikasi kontur, dan ukuran helm dengan menggunakan software solidwork 2005. Desain dan pabrikasi ini dilakukan di Pusat Riset Impak dan Keretakan Jurusan Teknik Mesin Fakultas Teknik USU, Pusat Riset Uji Material Jurusan Teknik Mesin Fakultas Teknik UNIMAL Lhokseumawe, dan Politeknik Negeri Lhokseumawe.

This thesis reports the result of design and fabrication of industrial helmet model of composite materials polymer of GFRP type of polyester (unsaturated resin) BTQN 157 EX with fibre of E-Glass ( Chop Strand Mat). At fabrication process of helmet, this composite was made with formation two fibre coat of CSM and was formed to follow the contour of anthropometry for human head with helmet moulding standard AS / NZS 1801 EN 397 SS 98 by using method of hand lay up. Moulding system of helmet was done separately, and four helmet wall side as wind channels were made. The result of static test has known the mechanical properties of base material of helmet, and to know the maximum stress of 277 MP and elasticity modulus price ( E) of 782 MPa were obtained by using apparatuses test Universal Ht-9502 Computer Hidrolic Testing Machine. The ergonomic testing of helmet by using apparatuses test of thermocouple, the result showed that the measurement of mean air temperature in helmet wall was 33.160C, and the weight of composite helmet after being produced was 365 grams by using digital SAUTER D-7470. For the test of strength of helmet with load of impact high-speed by using KOMPAK test apparatuses. Before test of helmet was done, the input bar was measured by using two gage technique to know the bigness of stress response of impact at input bar with pressure of 0.4 Mpa, and in distance of impact 60 mm, stress response at input bar is 362 MPa was obtained. The testing of helmet model [TSA] with upper impact, in distance of impact 60 mm, and strain gage at X direction, stress of impact of 64.43 MPa, and incident stress of 24.50 MPa were obtained. For the test of strength of helmet model [TSA] with upper impact, and variation of impact distance from 40 mm to 120 mm, position of strain gage at X direction, in distance of 15 mm from impact point, the stress response of impact produced was - 10.96 MPa, and for [DSA] helmet was - 21.61 MPa. While for the model of helmet [ TSA] with distance of impact 60 mm, and position of strain gage at Y direction, the stress respon of impact obtained was 67.77 MPa, and incident stress was 26.28 MPa. However, at distance of impact 140 mm, the stress response of impact was 91.89 MPa, and incident stress was 36.80 MPa. For the beside impact of helmet model [TSA] was – 6.61 MPa, and helmet model [DSA] was – 4.24 MPa. Then, re-designing for the construction of composite helmet model for clarifying joint contour, and helmet dimension by using solidwork 2005. This design and fabrication were done at Center Research of Impact and Fracture of Technical Engineering Faculty of USU, Center Research Test of Material Department, Technical Engineering Faculty of UNIMAL Lhokseumawe, and Politeknik Negeri Lhokseumawe.