CN201141222Y - Novel electric power line tower structure diagonal member - Google Patents

Abstract

Disclosed is a diagonal member for a transmission line iron tower, belonging to transmission line field, aiming at solving the problem in model selection of the section of the member in the structural design of a transmission line iron tower. The diagonal member is characterized in that the diagonal member introduces cold-bent angle iron with unequal legs, the ratio of length b1 of the long leg of the cold-bent angle iron to the length b2 of the short leg of the cold-bent angle iron is 1.45-1.65. When the thickness of the cold-bent angle iron with inner flanges is no more than 6mm, cold-bending intensity value f`=[1+Eta*(12*Gamma-10)*t/l*Theta(i)/2*Phi)]*f; wherein Eta is section factor of the steel; Gamma is the ratio of tensile strength to yield strength of the steel; n equals to 3 which is the number of the corners of the section; Theta(i) is the round angle corresponding to the i corner of the section; l is the length of the center line of the section; f is the tensile strength value of the steel without cold bending; t is the thickness of the cold-bent angle iron with unequal legs. When the wall of the cold-bent angle iron is more than 6mm and less than 16mm thick, amendment is necessary. If the transmission line iron tower is designed based on the intensity of the raw material, improvement in intensity resulting from cold bending can be used as safety stock.

Description

The oblique material of a kind of novel iron tower of power transmission line structure

Technical field

The utility model belongs to the transmission line of electricity design field, particularly at the selection issue of member section in the iron tower of power transmission line structure design.

Background technology

In transmission line tower structure, tiltedly material is the eccentric force member that can only single face be connected with main material, its supporting capacity P _CrCalculated length l is inversely proportional to, and I is directly proportional with second moment of area, can be P with formulae express _Cr=π ²EI/l ²Tiltedly the length of material is generally bigger, and particularly the oblique material member of body portion all adopts supplemental support to reduce calculated length, to improve its supporting capacity.When member adopts angle with equal legs, because it is the same with the second moment of area of free limb angle steel to support limb, the calculated length in the supporting plane will not enlarge markedly, and cause member significantly to reduce in the supporting capacity on this plane, start to control to make when the structure design selection and use.And adopt not angle with equal legs, manomelia plane to adopt supplemental support, to reduce calculated length, improve its bearing capacity; Though wide limb is a free limb, its moment of inertia is big than the manomelia moment of inertia, the also corresponding raising of its bearing capacity.The two is had complementary advantages, thereby the cross section property that has made full use of material is to improve the supporting capacity of oblique material.

For a long time, the oblique material of China's iron tower of power transmission line structure such as mostly selects for use at the limb hot-rolled angle steel, because the restriction of hot-rolled angle steel specification kind, also often has the situation of " little with big generation " in the design.So just cause oblique material cross section property not to be fully used, caused the steel waste, increased the weight of iron tower of power transmission line, be unfavorable for the iron tower of power transmission line optimum Design of Structure.And abroad, do not wait the application of limb hot-rolled angle steel on iron tower of power transmission line comparatively extensive, and show according to the related data statistics, use and do not wait the oblique material slenderness ratio λ of limb hot-rolled angle steel mostly greater than 120.

Owing to do not wait the limb hot-rolled angle steel to be subjected to the restriction of specification kind easily, in China's electric power pylon design, never applied, and cold-rolled forming section be the good approach that addresses this problem.The cold-rolled forming section structure is by changing the light section steel structure that its cross sectional shape improves mechanical property, adopt cold machining molding process, the flakiness ratio of shaped steel wallboard is restricted unlike hot-strip, therefore can not only thin but also widely, can produce the reasonable section shape of distribution of material optimum as required, open up main by cross sectional shape rather than increase the new way that material usage improves bearing capacity merely.Through cold worked steel, because processed part has stood plastic strain, material has experienced flow harden, and its mechanical performance is greatly improved, and yield strength and ultimate strength improve.

Utilize the unrestricted huge advantage of cold-rolled forming section cross section kind, can be according to actual needs, go not waiting limb clod wash angle steel to be applied in the design of the oblique material of electric power pylon.

Summary of the invention

The utility model at the oblique material of China's iron tower of power transmission line for a long time to wait limb hot-rolled angle steel, limited the present situation that the designer inquires into and uses new type of component to a great extent, proposed with clod wash not angle with equal legs as the solution of the oblique material of electric power pylon.

Do not wait limb clod wash angle steel as the iron tower of power transmission line of main material as shown in Figure 1, tiltedly material is by not waiting limb clod wash angle steel to form.

Do not wait limb clod wash angle steel to consider the influence of flow harden, its yield strength will have raising in various degree, when " Technical code for design of coldformed thin wall steel structures " is no more than 6mm for the cold-rolled forming section wall thickness in (GB50018-2002), consider the Intensity Design value f ' of effect of cold work.Adopt and do not wait limb clod wash angle steel; Do not wait the long limb length of limb clod wash angle steel b ₁With manomelia length b ₂The scope of ratio between 1.45～1.65;

When the lipped angle wall thickness is no more than 6mm in the described clod wash, consider the Intensity Design value of effect of cold work $f^{\&prime;}=[1+\frac{\mathrm{\&eta;}(12\mathrm{\&gamma;}-10)t}{l}\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}\frac{{\mathrm{\&theta;}}_{\mathrm{<figure-callout\; id="2"\; label="i"\; filenames="Y20072019048100071.png"\; state="\{\{state\}\}">i</figure-callout>}}}{2\mathrm{\&pi;}}]f,$ Wherein, η is a type mode coefficient, and γ is the ratio of the tensile strength and the yield strength of steel, and n is that the contained corner angle number in cross section is 3, θ _iBe i pairing angle of circumference of corner angle on the cross section, l is the length of kernel of section line; F is not for considering the steel strength design load of effect of cold work, and t is the thickness that does not wait limb clod wash angle steel.

When described clod wash angle steel wall thickness greater than 6mm simultaneously less than 16mm, revise, revised formula is:

$f^{\&prime;}=[1+\frac{\mathrm{\&eta;}(12\mathrm{\&gamma;}-10)\mathrm{tf}\left(t\right)}{l}\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}\frac{{\mathrm{\&theta;}}_i}{2\mathrm{\&pi;}}]f$

Wherein $f\left(t\right)=e^{\frac{\ln (\mathrm{\&beta;}/0.165)}{6}t-\ln \frac{\mathrm{\&beta;}}{0.165}},$ Remaining coefficient physical significance is the same, gets β=0.12 according to existing experimental data.

Two characteristics of the oblique material of the utility model iron tower of power transmission line: one) flow harden is improved a lot to not waiting limb clod wash angle steel intensity, effect of cold work generally can improve about 10% of design strength, if by raw material Intensity Design value iron tower of power transmission line is designed, then the intensity brought of effect of cold work improves and can be used as safety stock.Two) when not waiting limb clod wash angle steel and waiting limb hot-rolled angle steel area identical, do not wait the supporting capacity of the oblique material of limb clod wash angle steel bigger, thereby reduced the iron tower of power transmission line steel using amount with thickness.

Do not wait limb clod wash angle steel to be applied to and to note following some problem in the iron tower of power transmission line structure design, one) do not wait limb clod wash angle steel to be connected with bolt between the main material as oblique material, consider the influence of effect of cold work, end distance changes 2.0 times of diameters of bolt into by 1.5 times of original diameters of bolt; Two) in vertical force direction bolt center to member edge apart from minimum acceptable value, change 1.45 times of diameters of bolt into by 1.25 times of original diameters of bolt.When clod wash does not wait the oblique material of limb to be used for the iron tower of power transmission line structure, to satisfy above specific (special) requirements textural.

Description of drawings

Fig. 1 is an iron tower of power transmission line body of the tower structure chart, and wherein 1 is main material, and 2 is that oblique material, 3 is that horizontal material, 4 is auxiliary material.

Fig. 2 is the schematic cross-section of hot rolling angle with equal legs.

Fig. 3 is the not schematic cross-section of angle with equal legs of clod wash.

The specific embodiment

Describe an instantiation of the present utility model in detail below in conjunction with accompanying drawing, in the iron tower of power transmission line structure design, adopt and do not wait limb clod wash angle steel as the oblique material of electric power pylon.

Certain 220kV iron tower of power transmission line, limb hot-rolled angle steel (Q235) sectional dimensions such as the oblique material of certain section are 40mm * 40mm * 4mm, adopt and do not wait limb clod wash angle steel to carry out the iron tower of power transmission line structure design, the specification of this oblique material becomes 50mm * 30mm * 3mm.Do not wait limb clod wash angle steel and wait limb hot-rolled angle steel schematic cross-section as shown in Figures 2 and 3, cross section property sees the following form:

Specification	A(cm 2)	I x (cm 4)	I y(cm 4)	I x0(cm 4)	I y0(cm 4)
						Deng limb hot-rolled angle steel L50 * 50 * 4	3.90	9.26	9.26	14.68	3.82
Do not wait limb clod wash angle steel L60 * 40 * 3	2.85	10.78	3.98	12.64	2.13

Generally speaking, the oblique material that intersects adopts blind bolt to connect, and slenderness ratio is bigger, and the bending failure around parallel axes (X-axis obtains Y-axis) will take place under load action.If reasonable in design, do not wait the oblique material of limb clod wash angle steel that the steel product cross-sectional characteristic is fully used, improve the supporting capacity of oblique material.

Do not wait limb clod wash angle steel 60mm * 40mm * 3mm, consider the Intensity Design value of effect of cold work $f^{\&prime;}=[1+\frac{\mathrm{\&eta;}(12\mathrm{\&gamma;}-10)t}{l}\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}\frac{{\mathrm{\&theta;}}_{\mathrm{<figure-callout\; id="2"\; label="i"\; filenames="Y20072019048100071.png"\; state="\{\{state\}\}">i</figure-callout>}}}{2\mathrm{\&pi;}}]$ $f=[1+\frac{1.0\&times;(12\&times;1.58-10)\&times;3}{95.07}\&times;\frac{1}{4}]\&times;f=1.071\&times;205=219N/{\mathrm{<figure-callout\; id="2"\; label="mm"\; filenames="Y20072019048100071.png"\; state="\{\{state\}\}">mm</figure-callout>}}^2,$ Intensity Design value Deng limb hot-rolled angle steel 50mm * 50mm * 4mm is 215N/mm ², as calculated, be the oblique material of 2.774m for selected length, do not wait the oblique material of limb clod wash angle steel to wait the oblique material bearing capacity of limb hot-rolled angle steel to improve 8%, and the not weight saving 27% of the oblique materials of limb hot-rolled angle steel such as weight ratio of the oblique material of angle with equal legs of clod wash.Even do not consider the intensity raising that effect of cold work brings iron tower of power transmission line is not designed, the intensity that clod wash brings improves the safety stock that can be used as the electric power pylon structure.

The analysis showed that, compare with traditional oblique material of hot rolling angle with equal legs that clod wash not angle with equal legs can improve the bearing capacity of electric power pylon, effectively reduces electric power pylon weight, obtains significant economic benefit. In addition, cold bending angle iron is not subjected to specification limits man-hour adding, and offers convenience for the iron tower of power transmission line designer when design, should apply.

Claims (2)

1, the oblique material of a kind of iron tower of power transmission line structure is characterized in that, adopts and does not wait limb clod wash angle steel; Do not wait the long limb length of limb clod wash angle steel b ₁With manomelia length b ₂The scope of ratio between 1.45～1.65;

When the lipped angle wall thickness is no more than 6mm in the described clod wash, consider the Intensity Design value of effect of cold work $f^{\&prime;}=[1+\frac{\mathrm{\&eta;}(12\mathrm{\&gamma;}-10)t}{l}\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}\frac{{\mathrm{\&theta;}}_i}{2\mathrm{\&pi;}}]f,$ Wherein, η is a type mode coefficient, and γ is the ratio of the tensile strength and the yield strength of steel, and n is that the contained corner angle number in cross section is 3, θ _iBe i pairing angle of circumference of corner angle on the cross section, l is the length of kernel of section line; F is not for considering the steel strength design load of effect of cold work, and t is the thickness that does not wait limb clod wash angle steel;

When described clod wash angle steel wall thickness greater than 6mm simultaneously less than 16mm, revise, revised formula is:

$f^{\&prime;}=[1+\frac{\mathrm{\&eta;}(12\mathrm{\&gamma;}-10)\mathrm{tf}\left(t\right)}{l}\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}\frac{{\mathrm{\&theta;}}_i}{2\mathrm{\&pi;}}]f$

Wherein $f\left(t\right)=e^{\frac{\ln (\mathrm{\&beta;}/0.165)}{6}t-\ln \frac{\mathrm{\&beta;}}{0.165}},$ Remaining coefficient physical significance is the same, gets β=0.12 according to existing experimental data.

2, the oblique material of iron tower of power transmission line structure according to claim 1 is characterized in that: not waiting limb clod wash angle steel is 2.0 times of diameters of bolt as the distance of the bolt link between oblique material and the main material; Force direction bolt center to member edge is 1.45 times of diameters of bolt apart from minimum acceptable value in vertical.

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