CN104316230B - Method and device for measuring vector force borne by cylindrical beam - Google Patents

Abstract

The invention relates to a method and device for measuring vector force borne by a cylindrical beam. One end of the cylindrical beam is fixed to a fixed support. A cylindrical beam section where a vector force action point is located is known. The method is characterized by comprising the steps that four resistance strain gages are arranged at the position, between the vector force action point and the fixed support, on the surface of the cylindrical beam, located on the same circumference of the cylindrical beam at the interval of 90 degrees and connected into a bending strain detection circuit of a detection device; when the vector force acts, the four resistance strain gages each have the stretching and compression combined effect. The bending linear strain of the position where the resistance strain gages are located is obtained through a detection circuit, and then the direction and magnitude of the vector force borne by the cylindrical beam are obtained through calculation. The characteristics of the vector force borne by the cylindrical beam is represented by one-point bending strain, the device is simple in measuring structure, convenient to install and operate, and capable of being widely applied to measurement of vector force borne by various cylindrical beams.

Description

Vectorial force measuring method and device suffered by a kind of cylinder beam

Technical field

The present invention relates to a kind of vectorial force measuring method and device, especially with regard to a kind of cylinder based on resistance strain gage Vectorial force measuring method and device suffered by beam.

Background technology

For sail-assisted propulsion boats and ships, in order to enable, sail active force is big in direction of ship travel stress, boats and ships are laterally square Little to stress, then need to measure wind direction and the wind speed of relative ship course, and combine the aerodynamic characteristics of sail, calculate Boosting power, the size of cross force suffered by the optimal corner of sail and boats and ships.The boosting power that marine navigator produces according to sail and The size of cross force, adjusts marine main engine rotating speed and rudder angle, it is ensured that sail-assisted propulsion boats and ships travel in optimum condition.Sail active force The traditional method measured is the wind speed and direction by measuring relative boats and ships, and the aerodynamic characteristics in conjunction with sail obtains.Wind speed The measurement of wind direction is generally adopted by wind speed wind direction sensor, but owing to boats and ships motor process existing pitching, rolling and heel Impact, certain error can be there is in wind speed and direction detected value, thus cause calculated boats and ships boosting power and cross force with There is error in actual value, this error can affect marine navigator's manipulation to boats and ships, and then it cannot be guaranteed that ship running is Good operating mode, even produces adverse consequences when error is big.Therefore, in the measurements, accurate sail active force can how be obtained, right For sail-assisted propulsion boats and ships manipulate, it is very important.

Summary of the invention

For the problems referred to above, it is an object of the invention to provide one and can directly obtain cylinder beam stress size and stress side To cylinder beam based on resistance strain gage suffered by vectorial force measuring method and device.

For achieving the above object, the present invention takes techniques below scheme: vectorial force measuring method suffered by a kind of cylinder beam, it Comprising the following steps: 1) cylinder beam periphery circumference sustained height between cylinder beam stress application point and the strong point is uniformly arranged Four identical resistance strain gages；2) set relative two resistance strain gage as one group, often group resistance strain gage respectively with two Equal resistors constitutes differential bridge arm circuit, and the given voltage of differential bridge arm circuit is identical；3) cylinder is acted on according to vectorial force Beam and cause cylinder deflection of beam to strain, drive the stretching of four resistance strain gages and compression, four resistance strain gage resistances to occur Change；The change of resistance strain gage resistance drives differential bridge arm circuit to produce differential voltage, and combines the change of resistance strain gage resistance Changing the formula between line strain, formula, resistance strain gage institute between differential voltage and resistance strain gage change in resistance are in place Put line strain formula, obtain the corresponding vectorial force angle of action；4) by resistance strain gage place section turn moment formula, line strain public affairs Formula, obtains vectorial force size suffered by cylinder beam.

The relative each self-corresponding change in resistance of two resistance strain gages is equal in magnitude, symbol is contrary.

Described step 3) in: the formula between resistance strain gage change in resistance and line strain:Wherein, Δ R For resistance strain gage change in resistance value, R be the initial resistance of resistance strain gage, K be the sensitivity coefficient of resistance strain gage, ε be resistance The line strain of cylinder beam position, foil gauge place；Formula between differential voltage and resistance strain gage change in resistance:Wherein, Δ U is differential voltage, U₀Given voltage for differential bridge arm circuit；Resistance strain gage institute is in place Put line strain formula:Wherein, M be resistance strain gage place section turn moment, E be cylinder Beam elastic modelling quantity, D be cylinder beam cross-sectional diameter, y be the distance of resistance-strain pitch of fins cylinder neutral line, θ be resistance strain gage And the angle between neutral line；Resistance strain gage place section turn moment formula: M=FL, wherein, F be amount of force to be measured, L is the force position distance to cross section, resistance strain gage place.

A kind of realize the device of vectorial force measuring method suffered by cylinder beam, it is characterised in that: it includes some detector units With a display unit；Described detector unit is electrically connected described display unit；Described detector unit acts on circle for detection The size and Orientation of the vectorial force on post beam, and it is transferred to described display unit, show cylinder by described display unit The size and Orientation of the vectorial force suffered by beam.

Described detector unit includes testing circuit and microprocessor；Described testing circuit electrically connects described microprocessor；Institute Stating testing circuit and use differential bridge arm circuit, this differential bridge arm circuit is between cylinder beam stress application point to be measured and the strong point Cylinder beam periphery circumference sustained height be uniformly arranged four identical resistance strain gages, and two relative resistance strain gages are One group, this differential bridge arm circuit that often group resistance strain gage is constituted with two equal resistors respectively；Described testing circuit will detection Differential wave send described microprocessor to, described microprocessor obtains the size of suffered vectorial force on cylinder beam through processing And direction.

Described microprocessor uses MCS-51 single-chip microcomputer.

Due to the fact that and take above technical scheme, it has the advantage that 1, apparatus of the present invention are at vectorial force application point And four resistance strain gages are set on the cylinder beam surface between hold-down support, and adjacent two resistance strain gages are separated by 90 °, and By two relative differential bridge arm circuit of access, when vectorial force effect, four resistance strain gages have stretching and compression respectively Compound action, the output voltage changing value that apparatus of the present invention are obtained by differential bridge arm circuit measurement, indirectly obtain resistance should Become the sweep strain of sheet position, and process through detection controller, it is thus achieved that vectorial force size and direction suffered by cylinder beam, Device architecture of the present invention is simple, be easily installed, easy to operate, hardware device is few and production cost is low.2, the present invention Device is applied to sail-assisted propulsion boats and ships sail Force measurement, uses cylindrical sail mast, is measured by differential bridge arm circuit Method, obtains the sweep strain of resistance strain gage position on mast, calculates and obtains the suffered arrow of sail-assisted propulsion boats and ships mast Measuring one's own ability, the final sail active force that obtains, to the boosting power of boats and ships and cross force, overcomes and uses traditional wind speed wind direction sensor Measure and calculate the inaccuracy problem of sail active force method, easily facilitate the marine navigator behaviour to sail-assisted propulsion boats and ships Control.3, apparatus of the present invention measure vectorial force by the method measuring sweep strain, compared with traditional force measuring instrument device, On the basis of can measuring stress size, Impact direction can be obtained again, therefore, present invention could apply to all cylinder beam institutes Measured by vectorial force.

Accompanying drawing explanation

Fig. 1 is the structural representation of apparatus of the present invention

Fig. 2 is the testing circuit schematic diagram of the present invention

Fig. 3 is the application state schematic diagram of apparatus of the present invention

Fig. 4 is the cylinder beam section schematic diagram by vectorial force application point

Fig. 5 is the cylinder beam section schematic diagram by resistance strain gage

Detailed description of the invention

With embodiment, the present invention is described in detail below in conjunction with the accompanying drawings.

The present invention is for measuring the stressing conditions of sail mast, and sail mast uses cylindrical shape, and therefore wind is to sail Active force equivalence can become the stress of mast place axis certain point, thus sail stress problem is converted into cylinder beam Stress problem, therefore the present invention is to directly obtain cylinder beam stress size and the measuring method of Impact direction and device.

The inventive method comprises the following steps:

1) the cylinder beam periphery circumference sustained height between cylinder beam stress application point and the strong point is uniformly arranged four Identical resistance strain gage, the most adjacent two resistance strain gages are divided into 90 ° mutually；

2) set relative two resistance strain gage as one group, often group resistance strain gage constitute with two equal resistors respectively poor Move bridge arm circuit, and the given voltage of differential bridge arm circuit is U₀；

3) act on cylinder beam according to vectorial force and cause cylinder deflection of beam to strain, drive four resistance strain gage stretchings And compression, four resistance strain gage resistances change；The relative each self-corresponding change in resistance size of two resistance strain gages Equal, symbol is contrary；The change of resistance strain gage resistance drives differential bridge arm circuit to produce differential voltage, and combines resistance-strain Formula between sheet change in resistance and line strain (Wherein, Δ R be resistance strain gage change in resistance value, R be resistance The initial resistance of foil gauge, K be the sensitivity coefficient of resistance strain gage, ε be the line strain of cylinder beam position, resistance strain gage place), poor Galvanic electricity pressure with resistance strain gage change in resistance between formula (Wherein, Δ U is differential voltage, U₀For differential The given voltage of bridge arm circuit), resistance strain gage position line strain formula (Its In, M be resistance strain gage place section turn moment, E be cylinder beam elastic modelling quantity, D be cylinder beam cross-sectional diameter, y be that resistance should Become the distance of pitch of fins cylinder neutral line, θ is the angle between resistance strain gage and neutral line), obtain corresponding vectorial force effect Angle；

4) by resistance strain gage place section turn moment formula, (M=FL, wherein F is that amount of force to be measured, L are for making Distance with force to cross section, resistance strain gage place), line strain formula ( ), justified Vectorial force size suffered by post beam.

As it is shown in figure 1, apparatus of the present invention include some detector units 1 and a display unit 2.Detector unit 1 is used for detecting Acting on the vectorial force on cylinder beam, display unit 2 is for showing the vectorial force on cylinder beam；Detector unit 1 is electrically connected Display unit 2.

Detector unit 1 includes testing circuit 11 and microprocessor 12；Testing circuit 11 electrically connects microprocessor 12.

As in figure 2 it is shown, testing circuit 11 is two differential bridge arm circuit, its given voltage is U₀, this differential bridge arm circuit Constitute as follows: the cylinder beam periphery circumference sustained height between cylinder beam stress application point to be measured and the strong point is uniformly arranged four Individual identical resistance strain gage, the most adjacent two resistance strain gages are separated by 90 °；If relative two resistance strain gages are one group； Often group resistance strain gage constitutes differential bridge arm circuit with two equal resistors respectively.When there being vectorial force to act on cylinder beam, meeting Causing cylinder deflection of beam to strain, four resistance strain gages have stretching and the compound action of compression accordingly, and four resistance should Becoming sheet resistance to change, the change of resistance strain gage resistance drives differential bridge arm circuit to produce differential voltage, testing circuit 11 Differential voltage is sent to microprocessor 12.Between built-in four the resistance strain gage change in resistance of microprocessor 12 and line strain Computing formula, the computing formula between differential voltage and resistance strain gage change in resistance, Stress calculation formula, resistance strain gage institute In section turn moment computing formula, it is calculated the angle of action and the size of vectorial force suffered by cylinder beam, and it is single to be transferred to display Unit 2.

In above-described embodiment, microprocessor 12 is preferably MCS-51 single-chip microcomputer.

Display unit 2 is display screen, for showing the angle of action and the size of vectorial force suffered by cylinder beam.

It is further illustrated by the examples that follow the operation principle of the present invention:

As it is shown on figure 3, cylinder beam 3 one end is fixed on hold-down support 4, it is known that cutting of vectorial force application point place cylinder beam Face 31, on the cylinder beam surface 32 between vectorial force application point and hold-down support 4, arranges four resistance strain gages 5,6,7,8, Corresponding resistance value is respectively R_f、R_b、R_l、R_r, four resistance strain gages are positioned on the same circumference of cylinder beam 3 outer surface, and phase 90 ° of interval mutually.

In whole cylinder beam 3, with resistance strain gage 6 (R_bOn the basis of), setting fan section, 4 right angles, the present invention is with suitable Clockwise arranges fan section and illustrates.

As shown in Figure 4, if resistance strain gage 6 (R_b) and resistance strain gage 7 (R_lCovering of the fan scope between) is Ith district, and resistance should Become sheet 7 (R_l) and resistance strain gage 5 (R_fCovering of the fan scope between) is IIth district, resistance strain gage 5 (R_f) and resistance strain gage 8 (R_rCovering of the fan scope between) is IIIth district, resistance strain gage 8 (R_r) and resistance strain gage 6 (R_bCovering of the fan scope between) is IVth district.

Set the initial resistance of four resistance strain gages as:

R_f0=R_b0=R_l0=R_r0=R₀ (1)

As in figure 2 it is shown, be oppositely arranged two resistance strain gages one group, i.e. resistance strain gage 5 (R_f) and resistance strain gage 6 (R_b) one group, resistance strain gage 7 (R_l) and resistance strain gage 8 (R_r) one group, often group resistance strain gage respectively with two equal resistors R₁Constituting differential bridge arm circuit, the given voltage of differential bridge arm circuit is U₀, two differential bridge arm circuit constitute testing circuit 11。

If vectorial forceAct on Ith district, due to vectorial forceEffect, causes the bending strain of cylinder beam 3 so that resistance Foil gauge 6 (R_b) and resistance strain gage 7 (R_l) tension, resistance strain gage 5 (R_f) and resistance strain gage 8 (R_r) pressurized, and relative Two each self-corresponding change in resistance of resistance strain gage is equal in magnitude, symbol contrary, and i.e. corresponding change in resistance situation is as follows:

R_f=R_f0-ΔR_f (2)

R_b=R_b0-ΔR_b (3)

R_l=R_l0-ΔR_l (4)

R_r=R_r0-ΔR_r (5)

Wherein, Δ R_fIt is resistance strain gage 5 (R_f) change in resistance size, Δ R_bIt is resistance strain gage 6 (R_b) change in resistance is big Little, Δ R_lIt is resistance strain gage 7 (R_l) change in resistance size, Δ R_rIt is resistance strain gage 8 (R_r) change in resistance size.

Resistance strain gage 5 (R_f) and resistance strain gage 6 (R_b) line strain size be ε₁, due to simply intermediate variable, therefore No longer describe in detail；Resistance strain gage 7 (R_l) and resistance strain gage 8 (R_r) line strain size be ε₂, due to simply intermediate variable, Therefore no longer describe in detail；The sensitivity coefficient of four resistance strain gages is K, then:

$\frac{{\mathrm{\ΔR}}_b}{R_{b0}}=-\frac{\mathrm{\Δ}{R}_f}{R_{f0}}={\mathrm{K\ϵ}}_1---\left(6\right)$

$\frac{{\mathrm{\ΔR}}_l}{R_{l0}}=-\frac{\mathrm{\Δ}{R}_r}{R_{r0}}={\mathrm{K\ϵ}}_2---\left(7\right)$

In testing circuit 11, owing to the change of resistance strain gage resistance causes differential bridge arm circuit to produce differential voltage, And differential voltage is respectively as follows:

${\mathrm{\ΔU}}_1=(\frac{R_0+{\mathrm{\ΔR}}_b}{2R_0}-\frac{R_1}{{2R}_1})U_0=\frac{U_0}{2}\frac{{\mathrm{\ΔR}}_b}{R_0}=\frac{U_0}{2}{\mathrm{K\ϵ}}_1---\left(8\right)$

${\mathrm{\ΔU}}_2=(\frac{R_0+{\mathrm{\ΔR}}_l}{{2R}_0}-\frac{R_1}{{2R}_1})U_0=\frac{U_0}{2}\frac{{\mathrm{\ΔR}}_l}{R_0}=\frac{U_0}{2}{\mathrm{K\ϵ}}_2---\left(9\right)$

Wherein, Δ U₁It is resistance strain gage 5 (R_f) and resistance strain gage 6 (R_b) change in resistance and the differential voltage that causes； ΔU₂It is resistance strain gage 7 (R_l) and resistance strain gage 8 (R_r) change in resistance and the differential voltage that causes.

Cylinder beam 3 neutral line radius of curvature is ρ, and according to line strain formula, cross section, resistance strain gage place is at neutral line y Line strain ε be:

$\mathrm{\ϵ}=\frac{y}{\mathrm{\ρ}}---\left(10\right)$

As it is shown in figure 5, resistance strain gage 5 and the resistance strain gage 6 distance away from neutral line z are y₁, resistance strain gage 7 (its line strain is ε₁) and resistance strain gage 8 (its line strain is ε₂) distance away from neutral line z is y₂, therefore ${\mathrm{\ϵ}}_1=\frac{y_1}{\mathrm{\ρ}},{\mathrm{\ϵ}}_2=\frac{y_2}{\mathrm{\ρ}}.$

The elastic modelling quantity of cylinder beam 3 is E, and according to Hooke's law, resistance strain gage place section stress σ is:

$\mathrm{\σ}=\mathrm{E\ϵ}=E\frac{y}{\mathrm{\ρ}}---\left(11\right)$

Resistance strain gage place section turn moment M is:

$M={\∫}_A\mathrm{y\σdA}={\∫}_A\mathrm{yE}\frac{y}{\mathrm{\ρ}}\mathrm{dA}=\frac{E}{\mathrm{\ρ}}{\∫}_A{y}^2\mathrm{dA}=\frac{E}{\mathrm{\ρ}}{I}_z---\left(12\right)$

$\frac{1}{\mathrm{\ρ}}=\frac{M}{{\mathrm{EI}}_z}---\left(13\right)$

Wherein, as it is shown in figure 5, I_z=∫_Ay²DA is the rotary inertia of cross section, resistance strain gage place centering axle, neutral axis For z-axis, this axle passes through the cylinder beam axle center in cross section, resistance strain gage place, and vertical with vectorial force direction；Cylindrical cross-section is straight Footpath is D, then:

$I_z=\frac{{\mathrm{\πD}}^4}{64}---\left(14\right)$

Line strain ε can be obtained by formula (10), formula (13) and formula (14):

$\mathrm{\ϵ}=\frac{64M}{\mathrm{E\π}{D}^4}y---\left(15\right)$

As it is shown in figure 5, for resistance strain gage 6 (R_b) and resistance strain gage 7 (R_l) away from neutral line distance respectively y₁With y₂, it is stipulated that vectorial force angle α is vectorial forceWith resistance strain gage 6 (R_b) angle, and along the zone sequence divided Direction forward (and be just clockwise) increases (present invention in a clockwise direction as a example by explanation), and zero point (0 °) is vectorial force By resistance strain gage 6 (R_b) point to resistance strain gage 5 (R_f) direction, then:

$y_2=\frac{D}{2}\sin {\mathrm{\θ}}_2=\frac{D}{2}\sin \mathrm{\α}---\left(17\right)$

According to formula (15), formula (16) and formula (17), resistance strain gage 6 (R_b) and resistance strain gage 7 (R_l) line strain be:

${\mathrm{\ϵ}}_1=\frac{64M}{\mathrm{E\π}{D}^4}\·y_1=\frac{64M}{\mathrm{E\π}{D}^4}\·\frac{D}{2}\cos \mathrm{\α}=\frac{32M}{\mathrm{E\π}{D}^3}\cos \mathrm{\α}---\left(18\right)$

${\mathrm{\ϵ}}_2=\frac{64M}{\mathrm{E\π}{D}^4}\·y_2=\frac{64M}{\mathrm{E\π}{D}^4}\·\frac{D}{2}\sin \mathrm{\α}=\frac{32M}{\mathrm{E\π}{D}^3}\sin \mathrm{\α}---\left(19\right)$

According to formula (8), formula (9), formula (18), formula (19), vectorial force angle of action α can be obtained:

(1) if vectorial force () act on Ith district, R_b>R_f, R_l>R_r, then Δ U₁> 0 and Δ U₂> 0:

$\mathrm{\α}=\arctan \left|\frac{{\mathrm{\ΔU}}_1}{{\mathrm{\ΔU}}_2}\right|---\left(20\right)$

(2) if vectorial force () act on IIth district, R_b<R_f, R_l>R_r, then Δ U₁< 0 and Δ U₂> 0:

(3) if vectorial force () act on IIIth district, R_b<R_f, R_l<R_r, then Δ U₁< 0 and Δ U₂< 0:

(4) if vectorial force () act on IVth district, R_b>R_f, R_l<R_r, then Δ U₁> 0 and Δ U₂< 0:

If according to counterclockwise arranging fan section, then the vectorial force angle of action is set as increasing along counter clockwise direction forward Greatly, formula (20)～formula (23) are constant.

Cylinder beam stress cross section 31 is H with the distance of hold-down support 4, resistance strain gage place cylinder beam central cross-section 32 with The distance of hold-down support 4 is h, and the height of resistance strain gage self is l, then the moment M in cross section, resistance strain gage place is:

$M=F\&CenterDot;L=F\&CenterDot;\frac{1}{l}{\&Integral;}_{h-\frac{l}{2}}^{h+\frac{l}{2}}(H-x)\mathrm{dx}=F(H-h)---\left(24\right)$

According to formula (24), formula (18) and formula (8), obtain vectorial force size:

$F=\frac{\mathrm{E\&pi;}{D}^3\mathrm{\&Delta;}{U}_1}{16(H-h)U_{0}K\cos \mathrm{\&alpha;}}---\left(25\right)$

Vectorial force effect size F suffered by cylinder beam 3 and direction α can be drawn by above-mentioned calculating process, and will be mutually accrued Calculate program portable in microprocessor 12, the cylinder beam 3 finally drawn is exported to display unit by vectorial force size and Orientation 2, in order to observe.

Above-described embodiment is merely to illustrate the present invention, and the structure of the most each parts, connected mode and measuring method etc. are all Can be varied from, every equivalents carried out on the basis of technical solution of the present invention and improvement, all be not precluded within this Outside the protection domain of invention.

Claims (4)

1. a vectorial force measuring method suffered by cylinder beam, it comprises the following steps:

1) the cylinder beam periphery circumference sustained height between cylinder beam stress application point and the strong point be uniformly arranged four identical Resistance strain gage, resistance strain gage described in each two is spaced apart 90 °, between the first resistance strain gage and the second resistance strain gage Covering of the fan scope be Ith district, the covering of the fan scope between described second resistance strain gage and the 3rd resistance strain gage is IIth district, described Covering of the fan scope between three resistance strain gages and the 4th resistance strain gage is IIIth district, described 4th resistance strain gage and described first Covering of the fan scope between resistance strain gage is IVth district；

2) setting relative two resistance strain gage as one group, often group resistance strain gage constitutes differential bridges with two equal resistors respectively Arm circuit, and the given voltage of differential bridge arm circuit is identical, said two differential bridge arm circuit output voltage is respectively Δ U₁With ΔU₂；

3) act on cylinder beam according to vectorial force and cause cylinder deflection of beam to strain, drive four resistance strain gage stretchings and pressure Contracting, four resistance strain gage resistances change；The change of resistance strain gage resistance drives differential bridge arm circuit to produce differential electricity Pressure, and combine the formula between the line strain of resistance strain gage change in resistance and cylinder beam position, described resistance strain gage place, Formula between differential voltage and resistance strain gage change in resistance, the line strain formula of cylinder beam position, resistance strain gage place, Obtaining the corresponding vectorial force angle of action, the described vectorial force angle of action is

If Δ U₁> 0 and Δ U₂> 0, α=arctan | Δ U₁/ΔU₂|, i.e. thrust is in Ith district；

If Δ U₁< 0 and Δ U₂> 0, α=arctan | Δ U₁/ΔU₂|+90 °, i.e. thrust is in IIth district；

If Δ U₁< 0 and Δ U₂< 0, α=π+arctan | Δ U₁/ΔU₂|, i.e. thrust is in IIIth district；

If Δ U₁> 0 and Δ U₂< 0, α=arctan | Δ U₁/ΔU₂|+270 °, i.e. thrust is in IVth district；

4) by resistance strain gage place section turn moment formula, line strain formula, vectorial force size suffered by cylinder beam is obtained.

2. vectorial force measuring method suffered by a kind of cylinder beam as claimed in claim 1, it is characterised in that: two relative resistance The each self-corresponding change in resistance of foil gauge is equal in magnitude, symbol is contrary.

3. vectorial force measuring method suffered by a kind of cylinder beam as claimed in claim 1, it is characterised in that: described step 3) in:

Formula between resistance strain gage change in resistance and line strain:Wherein, Δ R is that resistance strain gage resistance becomes Change value, R be the initial resistance of resistance strain gage, K be the sensitivity coefficient of resistance strain gage, ε be cylinder beam position, resistance strain gage place The line strain put；

Formula between differential voltage and resistance strain gage change in resistance:Wherein, Δ U is differential voltage, U₀Given voltage for differential bridge arm circuit；

Resistance strain gage position line strain formula:Wherein, M is resistance strain gage Place section turn moment, E be cylinder beam elastic modelling quantity, D be cylinder beam cross-sectional diameter, y be that resistance-strain pitch of fins cylinder beam is neutral The distance of layer, θ are the angle between resistance strain gage and neutral line；

Resistance strain gage place section turn moment formula: M=FL, wherein, F be amount of force to be measured, L be that force position is to electricity The distance in resistance cross section, foil gauge place.

4. vectorial force measuring method suffered by a kind of cylinder beam as claimed in claim 2, it is characterised in that: described step 3) in:

Formula between resistance strain gage change in resistance and line strain:Wherein, Δ R is that resistance strain gage resistance becomes Change value, R be the initial resistance of resistance strain gage, K be the sensitivity coefficient of resistance strain gage, ε be cylinder beam position, resistance strain gage place The line strain put；

Formula between differential voltage and resistance strain gage change in resistance:Wherein, Δ U is differential voltage, U₀Given voltage for differential bridge arm circuit；

Resistance strain gage position line strain formula:Wherein, M is resistance strain gage Place section turn moment, E be cylinder beam elastic modelling quantity, D be cylinder beam cross-sectional diameter, y be that resistance-strain pitch of fins cylinder beam is neutral The distance of layer, θ are the angle between resistance strain gage and neutral line；

Resistance strain gage place section turn moment formula: M=FL, wherein, F be amount of force to be measured, L be that force position is to electricity The distance in resistance cross section, foil gauge place.