Using PC Crash simulation program to determine optimum width of access road

Invention Journal of Research Technology in Engineering & Management (IJRTEM) ISSN: 2455-3689 www.Ijrtem. com Volume 3 Issue 6 ǁ September-October 2019 ǁ PP 50-56

Using PC Crash simulation program to determine optimum width of access road 1, 1,2

Ján Mandelík, 2,Bohumil Šejnoha

Department of Transport Safety, University of Security Management in Košice, Košice, Slovak Republic

ABSTRACT:The article deals with the possibility to use the PC Crash simulation program in order to calculate the alternative movements of a vehicle when entering an access road of a private land from a public road. The article demonstrates a procedure of an expert on road transport and means of transport in calculations for individual types of vehicles that may actually enter the land in question. In addition, it shows the results of simulations which take into account real vehicle properties, such as the influence of the vehicle suspension on its movement, actual conditions of a drive-away of vehicles and their change of direction, i.e. a directional deviation of tyres, steering of individual wheels of the front axle and other influences on the final calculation. In conclusion, the outcome of described expert procedures and their impact on the final assessment are presented.

KEY WORDS: Simulation program, optimum vehicle movement, land, calculation of vehicle entry I.

INTRODUCTION

The PC Crash calculation program, designed to analyse accidents in road traffic, represents a calculation tool which by means of complex mathematical procedures, in particular the Kudlich-Slibard crash model, the impulse mirror method and moment mirror method, the kinetic drive simulation, as well as forward simulations enables to calculate the vehicle movement which could be considered sufficiently realistic. The vehicle movement simulations in this program are validated with respect to actual vehicle movements under specified conditions and, based on this, they are understood and recognized as practically identical. The use of the above program in order to carry out analyses of accidents involving vehicles, motorbikes, bicycles and pedestrians is generally known in various countries around the world and fully accepted by courts. Due to its features, the PC Crash program can also be used to solve problems not directly associated to car accidents. As shown below, it may be used to calculate the movement of a chosen vehicle and its manoeuvring when entering a private land from a public road in order to assess and determine the width of entry, assuming that the stated problem could not be solved comprehensively, accurately and efficiently enough in any other way with respect to time consumption.

The presented calculations include technical data of individual vehicles chosen for the simulation and the movement alternatives of manoeuvring and subsequent entry to the specified land, provided that the entry meets the condition of the smallest width possible.

II.

CALCULATION CONDITIONS

Calculation method:The analysis of the vehicle movement will be carried out by means of a calculation and the authorised PC-Crash program, ver.12,1, (the licence owner - Ing. JánMandelík, PhD.)via a forward calculation with a vehicle movement simulation until the final positions are reached, using a 3D mathematical model. The simulation results in the input values that describe the vehicle movement under specified conditions as precisely as possible. This program calculates the positions and speeds of the vehicles and any other kinetic variables necessary to assess the vehicle movement with high accuracy – taking possible real and accidental influences of ±5% into consideration, whereas in this particular case the value of -5% may not be taken into account (which results from the nature of the task).

Land: The situation is shown in Fig.1 and the measuring method is shown in Fig.2

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Using PC Crash simulation program to determine…

Figure 1: A view of the situation at the entry

Figure 2: Measuring of the land for calculation purposes

III.

RESULTS OF MEASUREMENT

gate width: 4,0 m width of the grass area by the road: next to the land P = 1,7 m, opposite the land O = 1,1 m road width: 5,2 m The calculation was made for the determined conditions, not considering extraordinary circumstances that would prevent or significantly obstruct manoeuvring of the vehicle (such as piled snow, etc.) i.e. for the given usable width of the road and grass area on the designated land.

For the entry of the vehicles it was necessary to consider their exit too, which could be performed as follows: • without subsequent turning on the public road, i.e. the entry with the front part and the exit by means of reversing with subsequent turning on the private land, i.e. the entry with the front part and the exit with the front part.

• From the technical point of view, turning on the private land would require the adequate space without obstacles, which is not possible for trucks in view of the planned construction and its use. The wheel movement trajectories are shown in ochre or black, the outline of the vehicles is shown in red.

Vehicles: Passenger vehicle: A calculation model of Skoda SuperB 2,5 TDi, shown in Fig.3, was used to calculate the movement of passenger vehicles.

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Using PC Crash simulation program to determine…

Figure 3: Skoda SuperB 2,5 TDi Technical data of Skoda SuperB 2,5 TDi Displacement: 2 496 cm3 Max. power: 114 kW (155 k) / 4 000 min.-1 Max. torque: 310 Nm / 1 400 min.-1 Max. speed: 213 km/h Acceleration 0 -- 100 km/h: 10,4 s Dimensions (mm): 4 805 x 1 765 x 1 470 Wheel base: 2 803 mm Kerb weight: 1 604 kg Turning diameter: 11,8 m B. Medium truck :A model of a three-axle medium truck with a platform body, shown in Fig.4, was used to calculate the movement of medium trucks.

TECHNICAL DATA OF PRAGA V3S Useful load 5510 kg Axle base (3 580+1 120) mm Wheel track - front axle 1 870 mm - rear axle 1 755 mm Length 6 910 mm Width 2 320 mm Height – over driver cab, without load 2 550 mm Height – over tarp, without load (2 780/2 970) mm Clearance height 400 mm Smallest track turning diameter 10,5 m Outline, outer turning diameter 18,0 m

Figure 4: Drawing and dimensions ofPragaV3S

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Relations between the turning diameter and the outline turning diameter of the vehicle that could be used for the calculationby means of equations [1] – lit.2.

[1]

IV.

CALCULATION OF VEHICLE MOVEMENTS

A. Calculation of movement of Skoda SuperB 2,5 TDi :The result of the calculation of possible alternatives of Skoda SuperB 2,5 TDientering the land by means of a forward movement is shown in Fig.5 and the result of the calculation of possible alternatives of this vehicle entering by means of reversing is shown in Fig.6 and Fig.7.

When entering with the front part the necessary width of the profile at the land border is3,0 m and when entering by means of reversing the necessary width of the profile at the land border is2,5 m.

Figure 5: A calculation of movement ofSuperB 2,5 TDiwhen entering with the front part – a view of the initial and final position, trajectories of wheel movements and width of its outline in a ground plan

Figure 6: A calculation of movement of Skoda SuperB 2,5 TDi when entering by means of reversing – a view of the initial and final position, trajectories of wheel movements

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Using PC Crash simulation program to determine‌ and width of its outline in a ground plan

Figure 7: A calculation of movement of Skoda SuperB 2,5 TDi when entering by means of reversing in 3D with a view of vehicle positions B. Calculation of movement of P V3S : The result of the calculation of possible alternatives of Praga V3S entering the land by means of a forward movement is shown in Fig.8 and the result of the calculation of possible alternatives of this vehicle entering by means of simple reversing is shown in Fig.9 and the result of the calculation of possible alternatives of this vehicle entering by means of repeated reversing and manoeuvring is shown in Fig.10. When entering with the front part the necessary width of the profile at the land border is 4,0 mfor the distance of up to 6,0 m and then 3,0 m and when entering by means of simple reversing the necessary width of the profile at the land border is4,0 m for the distance of up to 1,5 m and then 3,0 m and when entering by means of repeated reversing and manoeuvring the necessary width of the profile at the land border is3,3 m for the distance of up to 0,5 m and then 3,0 m.

Figure 8: A calculation of movement ofPraga V3S with the front part – a view of the initial and final position, trajectories of wheel movements

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Using PC Crash simulation program to determine… and width of its outline in a ground plan

Figure 9: A calculation of movement of Praga V3S by means of simple reversing – a view of the initial and final position, trajectories of wheel movements and width of its outline in a ground plan

Figure 10: A calculation of movement ofPraga V3S by means of repeated reversing and manoeuvring – a view of the initial and final position, trajectories of wheel movements and width of its outline in a ground plan

V.

CONCLUSION

Based on the calculations made in the PC Crash program we could effectively assess the actually necessary minimum profile width to enter the private land from the public road. With the possible movement of vehicles for the entry of passenger vehicles and medium trucks to the land and after considering any possible measurement and calculation errors, as well as other accidental influences of 5%,it was possible to conclude that with the minimum width of the access road of 3,0m + 5%, i.e. 3,15 m -3,2 m after rounding, the movement of the vehicles in question is possible without any restrictions and the width of the entry to the access road results from the estimated way of vehicle movement, as well as from the possibility of using the width of the adjacent parcel.

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REFERENCES 1.

2.

3.

PC Crash program – user manual VLK F.: Dynamikamotorovýchvozidel (Dynamics of motor vehicles), Czech republic, Brno, 2001, ISBN 80-238-5273-6 VLK F.: Koncepcemotorovýchvozidel (Concept of motor vehicles), Czech republic, Brno, 2001, ISBN 80-238-5276-0

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