AN ABSORBING ELEMENT OF A SAFETY TRAFFIC BARRIER AND A SAFETY TRAFFIC BARRIER COMPRISING SUCH AN ABSORBING ELEMENT

Abstract

 The present invention relates to an absorbing element (3) of a safety traffic barrier (1) having a form of a metal, bended thin-walled shape having a first mounting wall (31) provided with connecting means (311, 312) apt to be mounted to a guardrail (4) of a barrier (1), a second mounting wall (34a, 34b) being substantially parallel with respect to the first mounting wall (31) and having connecting means (341) apt to be mounted to a post (2) of a barrier (1), and two deformation walls (32, 33) connecting the first mounting wall (31) with the second mounting wall (34a, 34b). In order to enable for constructing safety traffic barriers of an improved shock-absorption capability each of the deformation walls (32, 33) is inclined at an acute inclination angle in the vertical plane, wherein the orientation of said acute inclination angle (α) is the same for the both deformation walls (32, 33), and furthermore the preferable inclination angle (α) of at least one of the deformation walls (32, 33) is within the range from 4 to 20°, preferably within the range from 5 to 10°, more preferably within the range from 6 to 8°, and particularly preferably amounts about 7°. The absorbing elements (3) of the present invention feature a simple and economical construction and ensure a simple and fast installation of safety traffic barriers (1). The present invention relates also to a safety traffic barrier (1) comprising such absorbing elements (3).

Description

[0001] The present invention relates to an absorbing element of a safety traffic barrier having a form of a metal bended thin-walled shape having a first mounting wall provided with connecting means apt to be mounted to a guardrail of a barrier, a second mounting wall being substantially parallel with respect to the first mounting wall and having connecting means apt to be mounted to a post of a barrier, and two deformation walls connecting the first mounting wall with the second mounting wall. The present invention also relates to a safety traffic barrier comprising a number of substantially vertical posts fixed in a substructure, a number of substantially horizontal shaped guardrails, and a number of such absorbing elements connecting the posts with the guardrails.

[0002] A safety traffic barrier is a safety device for traffic that is commonly disposed in dangerous locations for an absorption of an energy of a possible collision of a vehicle driving a road. Such a barrier constitutes also a physical obstacle that in a case of striking it by a vehicle may make a threat for health or life of traffic participants. The fundamental object of a safety traffic barrier is thus to provide a protection of health and life of traffic participants and providing safety for persons and buildings located in road surroundings.

[0003] Exemplary safety traffic barriers comprising various absorbing elements are disclosed inter alia in the following patent publications: DE4425182A1, EP1876301A1 or DE3640821C1.

[0004] The object of the present invention has been to provide an absorbing element of a safety traffic barrier that would enable for constructing safety traffic barriers of an improved shock-absorption capability, and additionally would feature a simple and economical construction and ensure a fast installation of safety traffic barriers.

[0005] In order to accomplish the aforementioned and other objects, according to the present invention it is provided an absorbing element of a safety traffic barrier as defined in the outset which is characterized in that each of the deformation walls is inclined at an acute inclination angle in the vertical plane, wherein the orientation of said acute inclination angle is the same for the both deformation walls.

[0006] The deformation walls are preferably inclined upward in the direction toward the first mounting wall, and said inclination angle is substantially the same for the both deformation walls.

[0007] In some preferred embodiments of the present invention, said inclination angle of at least one of the deformation walls is within the range from 4 to 20°, preferably within the range from 5 to 10°, more preferably within the range from 6 to 8°, and particularly preferably amounts about 7°.

[0008] Preferably at least one of the deformation walls has a substantially trapezoid shape, wherein the base angle of the trapezoid shape in the horizontal plane is within the range from 50 to 85°, preferably within the range from 60 to 80°, more preferably within the range from 69 to 73°, and particularly preferably amounts about 71°.

[0009] The proportion of the width of the first mounting wall along the edge of a transformation into the deformation wall to the length of the deformation walls in the horizontal plane is preferably within the range from 1.4 to 1.6, and the proportion of the height of the first mounting wall to the length of the deformation walls in the horizontal plane is preferably within the range from 0.5 to 0.7.

[0010] The radius of a curvature of the transition areas between the walls preferably corresponds to the thickness of the absorbing element. Thanks to that, in a case of forming the absorbing element from zinc-plated sheet metal, a probability of peeling off of zinc in bending areas is decreased.

[0011] According to the present invention it is also provided a safety traffic barrier which is characterized in that it comprises the above-defined absorbing elements.

[0012] The safety traffic barrier of the present invention preferably comprises at least one absorbing element, and preferably a number of absorbing elements having substantially trapezoid deformation walls, the longer edges of which are located at the guardrails.

[0013] Safety traffic barriers according to the present invention comprising absorbing elements according to the present invention feature a very good energy absorption level and yet providing a decrease of a working width (according to the standard PN-EN 1317).

[0014] The exemplary embodiment of the present invention is presented below in connection with the attached drawings on which

Fig. 1 presents an exploded view of an embodiment of a safety traffic barrier of the present invention depicting a connection of shape guardrails, an absorbing element and a post;

Fig. 2 presents the absorbing element in an axonometric view from the front side (Fig. 2a) and from the back side (Fig. 2b) respectively,

Fig. 3 presents the absorbing element respectively in a top view (Fig. 3a), in a back view (Fig. 3b), in a side view (Fig. 3c) and in a front view (Fig. 3d),

Fig. 4 presents the absorbing element in an unfolded state before press forming thereof in a top view, and

Fig. 5 presents the safety traffic barrier together with the absorbing element in a side view.

[0015] A safety traffic barrier 1, the fragment of which is schematically depicted in Figs. 1 and 5, comprises a number of substantially vertical posts 2 fixed in a substructure and projecting above the substructure at a height of about 60 cm. Absorbing elements 3 are mounted to the posts 2, wherein substantially horizontal shaped guardrails 4 are in turn mounted to the absorbing elements 3 such that the end sections of the adjoining guardrails 4 are inserted into each other. Particular elements of the barrier 1 are fastened by means of appropriate screws with nuts (that are not shown in Fig. 1) and additional washers 5.

[0016] As shown in Figs. 2 and 3, the absorbing element 3 has a form of a metal shape having a first mounting wall 31, from which are projected the upper deformation wall 32 and the lower deformation wall 33 substantially parallel to each other, from which in turn two coplanar walls 34a and 34b project, thus defining a second mounting wall. Alternatively the mounting walls 34a and 34b may be obviously projected facing against each other. Furthermore these mounting walls 34a and 34b may concreate a single second mounting wall, wherein the first mounting wall may be comprised of two separate mounting walls.

[0017] A longitudinal mounting opening 311 and two compensation openings 312 are formed in the first mounting wall 31, wherein in these openings may be situated heads of screws or nuts connecting the guardrails 4 with each other after an assembly of the barrier 1. Thanks to that the first mounting wall 31 completely adheres to the longitudinal mounting wall 41 of the guardrail 4 providing an increased surface of the contact with the guardrails in a moment of a collision impact. Similarly, the walls 34a and 34b of the second mounting wall have mounting openings 341 enabling for mounting the absorbing element 3 to the post 2 of the barrier 1. The longitudinal shape of certain chosen mounting openings compensates for thermal expansion of guardrails 4 and increases a tolerance of mounting of the barrier 1 elements.

[0018] The deformation walls 32 and 33 have substantially trapezoid shape, wherein the base angle β of the legs of the trapezoid shape in the horizontal plane amounts about 71°. Wherein the longer bases of the trapezoid deformation walls 32 and 33 adjoin with the first mounting wall 31 and are located at the guardrail 4.

[0019] As illustrated in Fig. 3c, the deformation walls 32 and 33 are inclined upward in the direction toward the first mounting wall 31 at an acute inclination angle α of about 7°. It is also visible that in the presented embodiment the absorbing element 3 features a symmetry with respect to the vertical plane crossing the center of the first mounting wall 31.

[0020] In the presented embodiment, the absorbing element 3 has the following dimensions:

• the width S₁ of the first mounting wall 31: 290 ± 2 mm;
• the height H of the first mounting wall 31: 119 ± 2 mm;
• the width S₂ of the first mounting wall 34a and 34b 115 ± 5 mm;
• the length D of the first mounting wall 32 i 33 in the horizontal plane: 198.5 ± 5 mm;
• the radius R of the bend of the walls 31, 32, 33 i 34 5 ± 1 mm;
• the thickness G of the walls 31, 32, 33 i 34 4 mm.

[0021] The proportion of the width S₁ of the first mounting wall 31 along the edge of a transition into the deformation wall 32, 33 to the length D of the deformation walls 32, 33 in the horizontal plane is within the range from 1.4 to 1.6, whereas the proportion of the height H of the first mounting wall 31 to the length D of the deformation walls 32, 33 in the horizontal plane is within the range from 0.5 to 0.7.

[0022] In the presented embodiment, the absorbing elements 3 according to the present invention are made of low-alloy steel S355J2 of an increased durability according to the standard EN 10025 and are fire-zinc-plated by a submersion method according to the standard EN ISO 1461.

[0023] As illustrated in Fig. 4, before subjected a press forming operation, the absorbing element 3 has an exceptionally simple shape that additionally ensures a minimization of a surface of post-production cutaway residues from a process of cutting out the absorbing elements 3 from a steel sheet.

[0024] For the safety traffic barrier according to the present invention as presented in Fig. 1, simulation tests and a practical crash test have been carried out.

[0025] The simulation tests have been carried out using a finite element method (FEM) by means of numerical tools indicated in the Table 1 and the numerical models indicated in the Tables 2 and 3. The practical crash test has been performed in the accredited laboratory facility Aisico (http://www.aisico.it). The test results are listed in the Table 4.

Table 2 - The FEM model of the bus vehicle

Name:	Unit	Value
A number of elements		53689
A number of nodes		54458
The vehicle mass	[kg]	12869
Dimensions on the axes
X	[mm]	12688
Y	[mm]	2569
Z	[mm]	3175
The wheel base X	[mm]	6506
The wheel base Y	[mm]	1856
The vehicle velocity	[km/h]	70.0
The accelerometer	[node index]	700002

Table 3 - The FEM model of a safety traffic barrier system (a safety traffic barrier, driven, single)

Name	Unit	Value
A number of elements		80184
A number of nodes		86590
The length of an installation	[m]	60
Ending		Boundary condition

Table 4 - Test results

Test No.		11/2015	12/2015	10/2015	1222-TB51
Test type		numerical simulation test			practical crash test
The inclination angle of deformation walls	[°]	0	20	7	7
The mass of a system	[kg/m]	28.4

SIMULATION CONDITIONS
The mass of a vehicle	[kg] [km/h]	12869			12702
The velocity of a vehicle		70			70.5
The angle of an impact	[°]	20

SIMULATION RESULTS
Maximal dynamic deformation	[m]	-	1.2	1.2	1.1
Maximal stable deformation	[m]	-	1.0	1.1	1.0
Normalized working width level		-	W5	W4	W4

BEHAVIOUR OF A SYSTEM
A system restrained and gave direction to a vehicle		NO	YES
An important part has been detached from a system or has been damaged		YES	NO
A fixation in the ground fulfills constructional requirements		YES

BEHAVIOUR OF A VEHICLE
A vehicle has breached a barrier		YES	NO
A vehicle has passed over a barrier		NO
A vehicle has overpassed the exit box line		NO
A vehicle leans over laterally in a test area		NO
A sizable vehicle part has been torn away		NO

[0026] The test results obtained indicate that an employment of the absorbing element according to the present invention in road and bridge safety traffic barrier systems makes the barrier systems unexpectedly featuring exceptionally preferable collision shock-absorption parameters.

[0027] As it turned out, the inclination angle α of the deformation walls of an absorbing element had a critical effect on the obtained results. The conducted simulation tests have confirmed that the inclination angle α of the deformation walls of an absorbing element amounting about 7° (the test 10/2015) ensured the best results in respect of a working width level that in accordance with the standard EN 1317 corresponded to the level W4 (1.2 m). For the inclination angle α amounting 0° (the test 11/2015) the barrier was not capable of holding down the vehicle. While an increase of the inclination angle α to a value of about 20° (the test 12/2015) has indeed enabled for holding down the vehicle, nonetheless it resulted in a significant deterioration of the working width that has reached the level W5 according to the standard EN 1317.

[0028] The results of the simulation test (the test 10/2015) for the inclination angle α of the deformation walls of an absorbing element amounting 7° have been verified and confirmed in a practical crash test (the test 1222-TB51).

[0029] The presented embodiment is not to be considered as limiting the intended scope of invention protection that is defined in the appended patent Claims.

[0030] The above described embodiment of the present invention is merely exemplary. The figures are not necessarily to scale, and some features may be exaggerated or minimized. These and other factors however should not be considered as limiting the spirit of the invention, the intended scope of protection of which is indicated in the appended patent Claims.

Claims

1. An absorbing element (3) of a safety traffic barrier (1) having a form of a metal, bended thin-walled shape having

a first mounting wall (31) provided with connecting means (311, 312) apt to be mounted to a guardrail (4) of a barrier (1),

a second mounting wall (34a, 34b) being substantially parallel with respect to the first mounting wall (31) and having connecting means (341) apt to be mounted to a post (2) of a barrier (1), and

two deformation walls (32, 33) connecting the first mounting wall (31) with the second mounting wall (34a, 34b),
characterized in that
each of the deformation walls (32, 33) is inclined at an acute inclination angle in the vertical plane, wherein the orientation of said acute inclination angle (α) is the same for the both deformation walls (32, 33).

2. The absorbing element according to Claim 1, characterized in that the deformation walls (32, 33) are inclined upward in the direction toward the first mounting wall (31).

3. The absorbing element according to Claim 1 or 2, characterized in that said inclination angle (α) is substantially equal for the both deformation walls (32, 33).

4. The absorbing element according to Claim 1 or 2 or 3, characterized in that said inclination angle (α) of at least one of the deformation walls (32, 33) is within the range from 4 to 20°, preferably within the range from 5 to 10°, more preferably within the range from 6 to 8°, and particularly preferably amounts about 7°.

5. The absorbing element according to any one of Claims 1-4, characterized in that at least one of the deformation walls (32, 33) has a substantially trapezoid shape, wherein the base angle (β) of the trapezoid shape in the horizontal plane is within the range from 50 to 85°, preferably within the range from 60 to 80°, more preferably within the range from 69 to 73°, and particularly preferably amounts about 71°.

6. The absorbing element according to any one of the preceding Claims,
characterized in that the proportion of the width (S₁) of the first mounting wall (31) along the edge of a transformation into the deformation wall (32, 33) to the length (D) of the deformation walls (32, 33) in the horizontal plane is within the range from 1.4 to 1.6.

7. The absorbing element according to any one of the preceding Claims,
characterized in that the proportion of the height (H) of the first mounting wall (31) to the length (D) of the deformation walls (32, 33) in the horizontal plane is within the range from 0.5 to 0.7.

8. The absorbing element according to any one of the preceding Claims,
characterized in that the radius (R) of a curvature of the transition areas between the walls (31, 32, 33 and 34) corresponds to the thickness (G) of the absorbing element (3).

9. A safety traffic barrier (1) comprising

a number of substantially vertical posts (2) fixed in a substructure,

a number of substantially horizontal shaped guardrails (4), and

a number of absorbing elements (3) connecting the posts (2) with the guardrails (4),

characterized in that it comprises the absorbing element (3) according to any one of Claims 1-8.

10. The safety traffic barrier according to Claim 9, characterized in that it comprises the absorbing elements (3) according to Claim 5 having the longer edges of the trapezoid deformation walls (32, 33) located at the guardrails (4).

Drawing