Design and Fabrication of SNI Helmet on Free Fall Test Using the Ulrich Design Method

SNI helmets have the highest assessment criteria in the digestive process regarding design, production, and market-to-target buyers. The design of this helmet emphasizes functionality rather than aesthetics. Careful planning must be done because it is the primary goal of this research, the theoretical basis of the fourth and fifth editions of the Ulrich method of product design development with score screening and concept selection using the product design style to be able to find complex case problems with great detail and reduce large production costs because of solving cases by maximizing the results of planning and designing the third concept with a score of 3.4 and a rate of 13 is the best, and the concept was chosen because it excels in the four selected aspects. Hence, proceed to the fabrication process. In the following score assessment, it is hoped that the parameters will be much more detailed to maximize the function and get closer to the details of the assessment so that it can be valid and objective.


Introduction
Helmet hoods on the market that are standardized usually use materials that meet international standards' requirements.The types of materials commonly used are Thermoplastic materials, such as Polycarbonate (PC), Acrylonitrile butadiene styrene (ABS), ABS Alloy, and PC, as well as Polypropylene (PP) and High Impact Polystyrene (HIPS) materials [1].A good helmet is a helmet that can absorb impact or impact energy because the head is an essential part and needs high protection to minimize the risk of injury [2].90% of accidents that occur in traffic caused by two-wheeled motorcycle accidents mention that the brain is the part that often gets injured in the accident victim [3].So the correct function of a helmet is to protect motorcycle riders from head injuries during collisions and head collisions within the limits of the helmet's capabilities and conditions of impact.
This study is useful in assessing the resistance of helmets to certain types of head injury [4].SNI requires that the speed-free fall test at 4.6 and 6.5 must not have a test result above 300 G because it can result in a high risk of concussion and severe injury [5].Materials that have light but strong characteristics today and what people usually call composites are materials that are widely used in engineering application products such as airplanes, trains, ships, and so on.The process of making the 1 m_hakam@ppns.ac.id concept of laminate analysis, making hand layups to the characteristics of each composite using the basic theory of the mechanical principles of the 1993 edition of Gillchrist composite materials [6].

Method
This study uses 4 variables, namely the results of the assessment of ergonomic concepts, economic concepts, manufacturing concepts, and function concepts in the design concept assessment of each characteristic of the design concept made.The ergonomic concept measures the zebra continuity concept with grid 18, grid 36, and grid 72 to find the concept that has the best line continuity.Then the economic aspect assesses how well the concept is maximal in the production planning process with aspects of helmet weight estimation, a dry time during the lamination process, slope angle to the estimated use of 3d printing.
The following assessment is an assessment of the manufacturing process with many parameters, and the next time it is used in making the production process of a design for the future.The last assessment is an assessment of the concept of the function by using a free fall simulation on a head form that is subject to a design concept helmet that is dropped onto a flat anvil at the height of 2.3 meters with a maximum estimated speed of 4.6 and 6.5 [7].The free fall position on the helmet is carried out in the middle back regarding the crown, and SNI 1811 2007 is the A-A position.So that 1 position is analyzed in this study.Scoring criterion using 1-4 scale due to good 4 number and transparent selection is specified in Table 1 below.This study uses 4 variables, namely the results of the assessment of ergonomic concepts, economic concepts, manufacturing concepts, and function concepts in the design concept assessment of each characteristic of the design concept made.The ergonomic concept is measuring the zebra continuity concept with grid 18, grid 36, and grid 72 to find the concept that has the best.

Result and Discussion
The design is carried out by analysing the continuity of the curve on the helmet shell geometry design as a detector of the excellent quality of the geometry, whether it is smooth or not.Because the geometry is not appropriately arranged will have a harmful impact and a fatal effect on generating mesh in the simulation in software [8] [9].The results of the zebra curve analysis process using Autodesk Fusion 360 software are obtained and described in Table 3 and Figures 1, 2, and 3.   Obtained on a grid of 72, concepts 1, 2, and 3 have curves that look not perfectly contoured on the front of the helmet, but Concept 1 has a better surface than other design concepts.On grid 72, if the first 1265 (2023) 012002 IOP Publishing doi:10.1088/1755-1315/1265/1/0120024 black line is calculated from the front surface, concept 1 has 5 black lines that are not connected neatly, while concept 3 has 11 lines.The contour results can be accepted as long as the post-processing of the geometry simulation on the object is read and the number of face particles is known.So that the helmet can be used and is suitable for helmet users for the XL size, there is a miniature 3D helmet with a circumference of 620 mm.Economic values/weights for the economic aspects of each concept are explained by the data table as follows by calculating the required fiber requirements.The results of the assessment outcomes are obtained and described in Table 4 as follows.The manufacturing aspect is calculated by the need for catalysts and resins, known from the fiber demand data.The more the need, the faster the dry process, but the risk is high because the coated catalyst and resin can spill under the surface due to their liquid nature and vice versa [8].Suppose the process is fast then (√), and if it is slow, then (-) [10].The results of the assessment outcomes are obtained and described in Table 5 as follows.

Much Few Fast
Slow The next is the result of the simulation of the concept obtained from the ANSYS Workbench according to the reference before, with a peak of maximum acceleration on the headform [11].Test parameters such as the characteristics of the test equipment are regulated in sni 1811-2007 [5] and follow international rules in determining the calibration of the test to the best accuracy in the ability of the tool to obtain maximum acceleration results [12].The highest maximum acceleration drop value for each concept is obtained and formulated in Table 6 as follows.After finding the results of all analysis and design, each aspect is collected and categorized in the form of a rate with a value of 1 to 4 and a maximum score that adjusts to the total weight in percentage [13}.A good concept is a concept that has the highest score and weight [10].The concept assessment that has been carried out is described in Table 7 as follows.

Conclusion
Based on the research that has been done, it is known that the third concept has a better value than the previous concept.The third concept is superior in economic and manufacturing aspects to the second concept and is superior in terms of function compared with the first concept.The greater the score, the better the aspects obtained in a concept so that the concept can be continued to the following process: the production process or the re-screening of the concept [5].

Figure 1 .
Figure 1.18 th Grid results

Table 1 .
[3]ring Method on Batan Product Design[3] The parameters mentioned are dimension, thickness, and material of each concept specifications of the open-face helmet products are set in Table2as follows.

Table 3 .
Zebra Curvature Continuity Analysis results

Table 4 .
Intersection contact analysis results

Table 6 .
Function results of Max.Acceleration peak on simulation do

Table 7 .
The results of the concept assessment using the Ulrich method