JPS6183386A - composite cable material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to improvements in cable materials used in suspension bridges and the like.

[Conventional technology]

In suspension bridges and the like that are subject to civil engineering work, cables such as PC strands are used to support the bridge. The PC strand is formed by twisting piano wires together, and although the tensile strength is sufficiently large, the weight per unit length is also quite large.

[Problems to be solved by the invention]

Therefore, when the span of a suspension bridge is increased, the weight of the cable itself increases, and the tension applied to the cable increases. In addition, if the weight of the cable is large, the structure of the supporting columns that support it must also be strong, and for this reason, there is a limit to the length of a suspension bridge's span. Conventionally, this limit has been approximately 2 km. Therefore, in order to extend the span of suspension bridges, it has been desired to develop cables that are lightweight, have high strength, and are relatively low cost.

It is an object of the present invention to provide the above-mentioned light weight, high yield strength, and relatively low cost cable material.

[Means for solving problems]

To achieve the above object, the present invention seeks to construct a composite cable material from carbon strands made of carbon fibers and conventional PC strands.

That is, carbon fiber unit strands of a desired diameter are formed by twisting carbon fiber strands with a diameter of several μm or by hardening them with adhesives, resins, etc., and the carbon fiber unit strands and PC strands are combined to form a composite. Form the cable material. At this time, a plurality of unit strands are uniformly arranged within the cross section so that the two types of unit strands do not cause uneven stress burden. Furthermore, deterioration of the carbon strands due to ultraviolet rays can be prevented by wrapping the outer periphery of this composite cable material with a sheath such as polyester, or by arranging the carbon strands in the center and arranging the PC strands around the outer periphery.

[For production]

Regarding the functions of this composite cable material, the following ■ Religions use those shown in Table 1.

0 The stress strain curve shown in FIG. 7 is used.

However, as shown in FIG. 8, the strain C is the elongation Δt when the tensile stress P is applied to the sample 10 of the composite cable material divided by the length t of the sample.

■ Carbon strands and P in composite cable materials
It grows together with the C strand.

Table 1 When calculated under the conditions of (1) About proof strength Stress degree σ of carbon strand.

σ. =Ec・ε ε≦0.0048 ・・・・・・
(1) Stress degree σ of PC strand.

σ,=E,・ε ε≦0.0048 ・・・・・・
(2) Especially Ee, E is carbon strand, PC
is the elastic modulus of the strand.

Now, the ratio of carbon strands in the composite strand is expressed as an area ratio, and if the carbon ratio is γ, γ is A, /A Ao is the cross-sectional area of the carbon strand A is the cross-sectional area of the composite strand Tensile load of the composite strand P (ton) Expressing the relationship between the carbon ratio γ and the strain C as a parameter, P=γλσ + (1-γ)Aσp = γAEeg+(1-γ) AEpε = (γEe+(1-γ)lil:,)A・ε・...
...(3) Figure 9 (a) and (b) are graphs showing equation (3). Figure (a) is for carbon strand (1), and Figure (b) is for carbon strand (2). be. It can be seen that as the carbon content r increases, the stiffness of the strand and the maximum yield strength at the elastic limit increase.

(1) About weight It can be seen that as the carbon percentage γ increases, the weight decreases.

(1) Regarding proof stress, FIGS. 10 B and C are graphs of the proof stress ratio at g=0.0048 obtained in FIG. 9 using the carbon ratio γ as a parameter. B is carbon strand (1
), C is for the case (2).

(lv) Regarding cost Table 2 summarizes the yield strength and cost for each carbon ratio γ of the composite cable material.

However, it is assumed that the specific gravity is Z85 for iron, 1.8 for carbon, and the price is 10 C1u';l for iron, and 9 for carbon 7000 yen/.

JP-A-Sho G1-8338G (4) koλ Of the second table, the first graph shows the cost-related values.
Figure 1. In the figure, R is the cost per unit weight, S is the cost per unit proof stress in the case of carbon strand (1), and T
is a graph showing the case (2). Naturally, as γ increases, the cost increases rapidly.

[Embodiments of the invention]

FIG. 1 is a sectional view of a composite cable material showing one embodiment of the present invention. 1 is a carbon strand, 2 is a PC strand, and 3 is a sheath. As shown in the figure, a plurality of PC strands 2 are arranged around the outer periphery of a central carbon strand 1, and the outer periphery is protected with a sheath 3 made of polyester, for example.

Figures 2 to 5 are cross-sectional views showing other embodiments, where Figure 2 is a strand rope, Figure 3 is a strand lobe, Figure 4 is a locked coil rope, and Figure 5 is a parallel wire strand. It shows the type. FIG. 6 is a partially enlarged view of a parallel wire strand, and is an example of another arrangement of PC strands and carbon strands.

〔Effect of the invention〕

Since the cable materials used for suspension bridges are made of different types of strands with a high yield strength, such as the carbon strands of PC strands, as shown in Table 2, the cable materials with high yield strength and unit weight compared to cable materials made of PC strands are shown in Table 2. It became a matter of scale to provide cable materials with longer lengths and smaller weights.

As a result, as shown in Figure 12, it is predicted that the maximum span of a suspension bridge will be extended by a certain amount from the conventional 2 km. However, since the price of carbon fiber is currently high, it cannot be said that it is advantageous in terms of cost in the case of long spans. Large economic and social effects are expected.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a composite cable material showing one embodiment of the present invention, and Figs. 2 to 5 are sectional views showing other embodiments.
The figure shows a strand rope, Figure 6 shows a spiral rope, i
4 [1: Locked coil rope, FIG. 5 is a cross-sectional view of each of the parallel wire strands. FIG. 6 is a partially enlarged view of the parallel wire strands, and is an example of another arrangement of the PC strands and the carbon strands. Figure 7 is a graph showing the relationship between stress stress and strain, Figure 8 is an explanatory diagram of the tensile test of composite cable materials, Figure 9 is a graph showing the relationship between tensile reverse load and strain of carbon strands, and Figure 10. Figure 11 is a graph showing the unit length weight and yield strength ratio versus carbon content of composite cable material, Figure 11 is a graph showing various costs versus carbon content of composite cable material, and Figure 12 is the maximum span versus carbon content of composite cable material. and a graph showing the cost per unit yield strength. In the figure, 1 is a carbon strand, 2 is a PC strand, and 6
is a sheath, and 10 is a sample of composite cable material. Agent Patent Attorney Kimura San 5 Q qノ＊ 2:゛s@轡? l” Procedural amendment (
spontaneous) 1. Indication of the case Patent Application No. 198671 No. 59-198671 2, Name of the invention Composite cable material 3, Person making the amendment Relationship to the case Patent applicant name (412) Nippon Koukan Co., Ltd. 4, Agent address Toranomon, Minato-ku, Tokyo 2-21-19 Hidekazu 2
"Detailed description of the invention" and "Destruction of drawings r.1" of the Toranomon Building specification
1. ,? T) (1) In the 13th line of page 2 of the specification, amend the phrase ``formed by joining together'' to ``formed by joining or parallel to each other''. (2) In the first line of page 3 of the specification, "The span of the suspension bridge from such a surface" is amended to read "The span of the suspension bridge from that surface as well." (3) In the second line of page 3 of the specification, "The conventional limit for footbridges is approximately 2 km" is amended to read "There was." (4) On page 4, line 7 of the specification, ``The functions are as follows'' is amended to ``The functions are estimated under the following conditions.'' (5) Delete the line at the bottom of Table 1 on page 5 of the specification: "Calculated under the following conditions." (6) Page 5, line 12 of the specification [E here. , E, are carbon strands and PC struts" are corrected to "Here, EcIE are carbon strands and PCC struts, respectively." (7) "Now," from page 5, line 14 to page 5, line 15 of the specification.
If the ratio of carbon strands in the composite strand is expressed as an area ratio and the carbon ratio is γ, then ``Now, if the ratio of carbon strands in the composite strand is expressed as an area ratio and this is the carbon ratio r,'' to correct. (8) On page 6, line 14 of the specification, "Graph A is a composite cable" should be amended to "Graph ■ is a composite cable." (9) Page 7, line 1 to page 7, line 2 of the specification “Noga...
It is... ” is corrected to the following sentence. ``This is Figure 10 @ and θ. @ is for carbon strand (1) and ○ is for carbon strand (2).'' (
10, page 9, line 6 of the specification, ``Costs are increasing rapidly.'' is amended to ``Costs are increasing.'' (l]) "Carbon strand of PC strand" on page 10, line 4 of the specification is corrected to "PC strand and carbon strand." 0ri In the specification, page 10, line 7 to page 10, line 9, "The unit length..." has been amended to the following sentence. [The aim was to provide a cable material with a small weight per unit length. Comparing the length t at which the strand breaks under its own weight, it is t - σ. /ρ(au: breaking strength,
ρ: density). Therefore, when the conditions for the composite strand are incorporated into this equation, as shown in the graph shown in FIG. 11a, it is found that t increases rapidly as the carbon percentage increases. (13) Page 10, line 10 to page 10, line 1 of the specification
Correct line 7, "As a result, a great effect is expected on Figure 12." to the following sentence. [Also, it can be expected that the maximum span of a suspension bridge can be extended to a considerable extent compared to the conventional one, but Figure 12 shows the maximum span in that case and the cost per unit strength of the cable corresponding to that span under the following conditions. This is calculated and shown in the graph. Calculation conditions■ Cable cross-sectional area A=4430d■ Vertical
Distance f=8200
Weight of stiffening girder w = 225 k19/c
,rn■ Specific gravity Iron Z85, Carbon 1.
8 ■ Unit price Iron 100 yen Aψ, carbon 7000 yen Δ9 ■ Yield stress Iron 100 kg/d, carbon 450 kFJ Currently, the price of carbon fiber is high, so
Although it is hard to say that it is advantageous in terms of cost in the case of long spans,
For example, suspension bridges can be used to construct bridges in places where bridge construction was technically impossible in the past, and great economic and social effects are expected from aspects other than bridge construction. (14) Page 11, line 13 of the specification [Graph showing,
Fig. 12 is a graph showing ``Fig. α0 Add Figure 11a between Figures 11 and 12 as an attached corrected drawing.

Claims (5)

[Claims] (1) A composite cable material characterized by being formed by twisting, gluing, or bundling strands or ropes of multiple types of materials with different maximum proof strengths. (2) The composite cable material according to claim 1, wherein the materials are a PC strand and a carbon strand. (3) The composite cable according to claim 1, characterized in that, in the composite cable material made of the PC strand and carbon strand, the carbon strand is arranged in the center and the PC strand is arranged in the outer periphery. material. (4) The composite cable material according to claim 1, wherein the composite cable material is made of the PC strand and carbon strand, and the PC strand is arranged in the center. (5) The composite cable material according to claim 1, characterized in that, in the composite cable material comprising the PC strands and carbon strands, the PC strands and carbon strands are randomly arranged within the cross section.