IMPROVEMENTS IN RAILROAD RAIL PROFILE

Abstract

A profile for the composition of a railroad rail with the provision for at least one pair of webs in each profile of the rail, in addition to being provided with a set of cutouts of a plurality of geometric shapes that allow the crossing of wires and cables for several purposes. The webs arranged more laterally to the center of the rail provide greater stability to the rail the plurality of holes enables greater capacity to absorb stresses and vibrations, consequently, greater stability for the train, especially at high speeds. The adopted geometries also present a greater mechanical strength in relation to common rail profiles compared to the same amount of used material.

Claims

1. IMPROVEMENTS IN RAILROAD RAIL PROFILE, comprising a foot (11), a web (12) and a head (13); wherein the profile (10) provides that the web (12) is formed by at least three walls (12A), with two external walls (12a) being parallel to each other in order to maintain a spacing (x) for the arrangement of a central wall (12b) forming a triple web (12); lower ends of the walls (12A) of the web (12) have side branches (11a), directed in opposite directions to each other, making up the foot (11), while upper ends of said external walls (12a) are joined together per a single sector that makes up the head (13).

2. THE IMPROVEMENTS IN RAILROAD RAIL PROFILE according to claim 1, wherein the spacing (x) receives at least one central wall (12b), projecting from a lower face of the head (13); a free end (12c) is flush with a lower base of the side branches (11a).

3. THE IMPROVEMENTS IN RAILROAD RAIL PROFILE according to claim 1, wherein the external walls (12a) and the central wall (12b) receive holes or cutouts (14) of varied geometries and aligned with each other according to the crossing axis (E1).

4. THE IMPROVEMENTS IN RAILROAD RAIL PROFILE according to claim 3, wherein said cutouts (14) present varied dimensions and diverse shapes as well as being both concentric and eccentric to each other.

5. THE IMPROVEMENTS IN RAILROAD RAIL PROFILE according to claim 4, wherein the diverse shapes are circular, oblong or rectangular.

Description

BRIEF DESCRIPTION OF FIGURES

[0022] In order to obtain a better understanding of the features of the present invention and according to a preferential practical embodiment of the same, the attached description is accompanied by a set of drawings, where, in an exemplified way, although not limiting, its operation was represented:

[0023] FIG. 1 represents a perspective view of a first version of the innovative triple web profile for a railroad rail;

[0024] FIG. 2 shows a side view of a section of the rail in FIG. 1, illustrating some models of holes or cutouts for crossing cables and various wirings, as well as helping to reduce vibration, in which FIGS. 3 and 4 and 5 represent cross sections, as indicated in the previous figures;

[0025] FIG. 3 shows the cross-section front view of the triple web rail;

[0026] FIG. 4 shows the cross-section front view of the triple web rail, in which the section plane passes through the holes in the webs;

[0027] FIG. 5 represents a perspective view of a second version of the innovative profile, in this case, a double web profile for railroad rails; and

[0028] FIGS. 6 and 7 represent cross-sections performed on the rail of FIG. 5, showing the section of the double web in an integral way and another section of the double web provided with cutouts or holes.

[0029] FIG. 8 shows the result of the simulations of vertical loads with maximum stresses on the TR68 rails (A), on the double web rail (B) and on the triple web rail (C);

[0030] FIG. 9 shows the result of the simulations of the vertical loads with the maximum displacements in the TR68 rails (A), the double web rail (B) and the triple web rail (C);

[0031] FIG. 10 shows the stress distribution in the cross section of the TR68, double web and triple web rails at the load application point;

[0032] FIG. 11 shows the distribution of stresses generated by the vertical loading in the cross section of the TR68, double web and triple web rails at the load application point;

[0033] FIG. 12 shows the isometric view of the result of the simulations of horizontal loads with maximum stresses on the TR68 rails (A), the double web rail (B) and the triple web rail (C);

[0034] FIG. 13 shows the distribution of stresses generated by the horizontal loading in the cross section of the TR68, double web and triple web rails at the load application point;

[0035] FIG. 14 shows the isometric view of the result of the simulations of the horizontal loads with the maximum displacements on the TR68 rails (A), the double web rail (B) and the triple web rail (C);

[0036] FIG. 15 shows the distribution of displacements generated by the horizontal loading in the cross section of TR68, double web and triple web rails at the point of load application;

[0037] FIG. 16 shows the isometric view of the result of the simulations of the horizontal loads with the maximum stresses (A) and the maximum displacements (B) in the triple web rail with the presence of a hole in the web;

[0038] FIG. 17 shows the distribution of stresses (A) and displacements (B) generated by the horizontal loading in the cross section of triple web rails with the presence of a hole in the web;

[0039] FIG. 18 shows the isometric view of the result of the simulations of the vertical loads with the maximum stresses (A) and the maximum displacements (B) in the triple web rail with the presence of a hole in the web; and

[0040] FIG. 19 shows the distribution of stresses (A) and displacements (B) generated by the vertical loading in the cross section of triple web rails with a hole in the web.

DETAILED DESCRIPTION OF THE INVENTION

[0041] With reference to the illustrated drawings, the present invention comprises a railroad rail profile (10) of the type for laying and fixing on ties (not illustrated) for track rolling surface composition. Said profile (10) is made of steel or other similar material and consists of a foot (11), a web (12) and a head (13).

[0042] The profile (10) provides in a first embodiment that the web (12) is formed by two parallel walls (12a) with thicknesses W.sub.1 and W.sub.2, and in a second embodiment, in which the profile (10) presents an arrangement of a central wall (12b) with thickness W.sub.2 and two walls (12a) with thicknesses W.sub.1 and W.sub.3, forming a rail with a triple web (12).

[0043] The profile (10), in the form of a double or triple web, has a spacing (x) between the walls (12a) in the range of 4 to 45 mm. The webs (12) have a thickness (w1, w2 or w3) in the range of 13 to 18 mm, being preferably 9.71 mm for double web rails and 8 mm for triple web rails. In addition, it is also provided by the present invention that the webs of the double or triple rails still have different thicknesses in the same section of said rail. This variation is interesting in curved sections, where the train loads on the rails change substantially.

[0044] In addition, the webs (12) can have uniform dimensions, that is, equal dimensions for the walls (12a) in the double web rails or the same dimensions for the walls (12a) and central wall (12c) in the triple web rails, or variable dimensions between the walls (12a) in the double web rails or between the walls (12a) and/or central wall (12c) in the triple web rails, in order to adapt the rail for different loads, such as in curved sections.

[0045] The lower ends of the walls (12a) of the triple web have side branches (11a), directed in directions opposite each other, comprising the foot (11), while the upper ends of said walls (12a) are joined together by a single sector comprising the head (13).

[0046] In both embodiments, the walls (12a) and (12b) can receive holes or cutouts (14) of varied geometries and aligned with each other according to the crossing axis (E1), preferably located in the center of said walls, allowing the passage of wires/cables (Cb), as well as configuring mechanical means of absorption of stresses and vibrations.

[0047] Said cutouts can (14) present varied dimensions, in the range from AA to BB, and different shapes such as circular, oblong/oval and rectangular with rounded edges, as well as being both concentric and eccentric, wherein the cutouts (14) are preferably concentric, circular or ellipsoidal.

[0048] In addition, it is clear that for a technician skilled on the subject the dimensions of the heads, feet, height and total width of the rail can be changed according to the design requirements.

[0049] In this way, the present invention proposes railroad rail embodiments that are more resistant and have the same linear weight of a conventional rail.

[0050] Therefore, those skilled in the art will value the knowledge presented herein and will be able to reproduce the invention in the presented embodiments and in other variants, encompassed by the scope of the attached claims.

EXAMPLE OF EMBODIMENT

[0051] The embodiment presented herein is not intended to act as a limitation, but to exemplify the features of the invention.

[0052] One of the embodiments comprised by the present invention is made from the features of the TR68 rail provided by NBR 7590:2012. The TR68 rail is a rail with an approximate linear weight of 68 kg/m with a height of about 185.74 mm, width of the foot (11), head (13) and web (12) of 152.4 mm, 74 mm and 17.46 mm, respectively.

[0053] The profiles (10) evaluated are double web and triple web ones, maintaining the same dimensions of the head and foot of the TR68 rail, with a height of 159.54 mm and distance between the external surfaces of the walls (12a) of 35.42 mm, distance X of 8 mm for double web and 16 mm for triple web, thickness W.sub.1 and W.sub.2 of 13.71 mm for double web and W.sub.1 and W.sub.3 of 9.71 mm for the walls (12a) and W.sub.3 of 8 mm for the central wall (12b) of the triple web rail.

[0054] To emphasize the advantages proposed by the present invention, a mechanical simulation was performed between said TR68 rails, with double web and triple web, wherein they are made of steel with a density of 7833 kg.Math.m.sup.?3, modulus of elasticity of 199947.953 MPa, Poisson's coefficient of 0.290, yield stress of 262.001 MPa, maximum stress of 358.527 MPa and elongation of 0.

[0055] The spacing between ties is a variable that depends on several factors and that, in this comparison, should be considered as a fixed dimension. It is calculated as a function of the allowable stress on the ballast, the tamping area, the increased wheel load and the impact coefficient. In addition, it also depends on the type of material that the tie is made of (wood, concrete, steel, etc.) and on the gauge, as shown in Table 1. In this way, the spacing adopted is 0.70 m because it is the largest spacing that will cause the greatest stresses and strains in the rail.

TABLE-US-00001 TABLE 1 Tie spacing. Tie Gauge (m) Spacing (m) Wood 1.0 to 1.6 0.54 Bi-block concrete 1.0 to 1.6 0.60 Monoblock concrete 1.0 to 1.6 0.60 to 0.70 Steel 1.0 to 1.6 0.54 Recyclable (plastic) 1.0 to 1.6

[0056] The dimensioning of the rail was carried out using the simplified Talbot method, considering the inelastic supports with a spacing of 0.70 m, regardless of the distances between the axles of the cars (the most used in Brazil are 1575 mm, 1727 mm and 1828 mm).

[0057] The value of the load applied to the rail was defined based on the largest loads used in Brazilian railroads, which is 32 ton/axle. In addition, a safety factor of 2.5 was applied, resulting in a load of 40 ton on each rail.

[0058] The rail was modeled based on the dimensions provided in NBR 7590:2012 and the length of the modeled rail was determined based on the size and spacing of the ties. As a boundary condition, the model was truncated and crimped at the ends and supported in the contact with the ties. The load application region corresponds to the contact between the train wheel and the rail.

[0059] The computational mesh used in the analysis was constituted with elements of approximately 5 mm along the entire body and 1 mm in the regions demanding greater refinement (region of the double and triple rails slots). The total number of elements varies according to the analyzed profile. Table 2 presents the information of the used mesh.

TABLE-US-00002 TABLE 2 Computational mesh. Total number Total number Profile Element type of elements of nodes TR68 Tetrahedron 70529 114295 Double rail Tetrahedron 102448 165754 Triple rail Tetrahedron 127346 208538

[0060] In this work, the behavior of the rail for loads in the vertical and horizontal directions was evaluated. The vertical load comes from the weight of the train when the train passes over the rail and the weight of the rail itself (gravitational field), causing a deflection in the vertical direction. The horizontal load is present in the system when the train makes a turn on the rails. The analyzes carried out take into account only the static loads on the structure.

[0061] Three rail profiles subjected to a vertical load were simulated. The results were analyzed in terms of maximum stresses and strains and are presented below. As it is a comparative scenario between the profiles, the maximum allowable stresses of the material were not taken into account, since the purpose of the analysis is to comparatively evaluate the profiles, highlighting the one that presents the best distribution of stresses and the smallest displacement.

[0062] From the analysis of the results presented in FIG. 8, a stress concentration in the load application region and a dissipation of this stress by the rail web can be noted. No significant stress variations were observed between the rails. Likewise, the displacements observed in FIG. 9 also did not have significant differences between the profiles, which were in the range of 0.52 mm to 0.74 mm.

[0063] FIG. 10 and FIG. 11 present, respectively, the distribution of stresses and displacements in the cross section of the rail at the point of application of the load. There can be seen a change in the distribution of stresses and displacements, although with few significant differences between the profiles. Table 3 presents the comparisons of the maximum displacements.

TABLE-US-00003 TABLE 3 Comparisons of the maximum displacements. Profile Maximum displacement (mm) Variation (%) TR68 0.553 Double Rail 0.671 121.34 Triple Rail 0.746 134.90

[0064] For the horizontal loadings, three rail profiles subjected to a horizontal load were simulated. The results were analyzed in terms of maximum stresses and strains and are presented below. As it is a comparative scenario between the profiles, the maximum admissible stresses of the material were not taken into account, since the purpose of the analysis is to comparatively evaluate the profiles.

[0065] FIG. 13 shows the stress distribution in the simulated profiles. It is observed that the double rail and the triple rail generated a reduction of the maximum stresses of the rail. Likewise, FIG. 14 shows a reduction in the displacement of the double and triple profile rails. Compared with the TR68 rail, the displacement presented in the double and triple rails were, respectively, 64.33% and 68.94% as shown in Table 4.

TABLE-US-00004 TABLE 4 Comparisons of the maximum displacements Profile Maximum displacement (mm) Variation (%) TR68 6.24 Double Rail 3.77 60.42 Triple Rail 4.04 64.74

[0066] Double and triple profile rails with ? (6.35 mm) and ? (12.7 mm) diameter holes were simulated for the passage of power and data cables. The same horizontal and vertical loads as in the previous cases were applied. FIG. 16 through FIG. 19 show the stress and displacement results for the ? (12.7 mm) hole triple rail subjected to a horizontal load. Comparing with the results of the trail without the hole, there were no significant changes in the maximum values obtained. The same analysis can be observed for cases with a ? (6.35 mm) hole.

[0067] FIG. 18 stress and presents the displacement results for the triple rail with a ? (12.7 mm) hole subjected to a vertical load. Also, no changes were observed in stresses and displacements for both the ? (6.35 mm) and ? (12.7 mm) holes. It is observed that the insertion of punctual holes in the rails does not affect the global behavior of the system.

[0068] The simulation presented a comparative analysis of three train rails subjected to vertical and horizontal loading, where the maximum stresses and maximum displacements of the rails were comparatively evaluated.

[0069] It is observed that both the double rail and the triple rail present a stress reduction of approximately 22% and displacement reduction of approximately 32% when subjected to a horizontal load. As for the vertical load, the rails showed similar behavior.

[0070] Table 5 shows the dimension values of the different models of Vignole rails compared to the dimensions of a version of the double and triple web rails.

TABLE-US-00005 Weight Cross- Head - Web - Foot - Total per section Standard width thickness width height meter area model (mm) (mm) (mm) (mm) (kg/m) (cm.sup.2) TR 37 62.72 13.49 122.24 122.24 37.20 47.39 TR 45 65.09 14.29 130.18 142.88 44.65 56.90 TR 50 68.26 14.29 136.52 152.40 50.35 64.19 TR 57 69.05 15.88 139.70 168.28 56.90 72.56 UIC 60 72.00 16.50 150.00 172.00 60.21 76.70 GB 60 73.00 16.50 150.00 176.00 60.64 77.47 TR 68 74.61 17.46 152.40 185.73 67.41 86.52 DOUBLE 74.61 X = 8.00 152.40 159.54 67.41 86.52 WEB W.sub.1 = W.sub.2 = 13.71 or X + (W.sub.1 + W.sub.2) < Head Width TRIPLE 74.61 Y = 4.00 152.40 159.54 67.41 86.52 WEB W.sub.1 = W.sub.3 = 9.71 and W.sub.2 = 8.00 or 2*Y + (W.sub.1 + W.sub.2 + W.sub.3) < Head Width 140RE 76.20 19.05 152.40 185.68 69.50 88.09 141RE 77.79 17.46 152.40 188.91 69.79 88.38