CN103543018B - A kind of analytical approach of vehicle frame load-carrying properties and device - Google Patents

Abstract

The invention provides a kind of analytical approach of vehicle frame load-carrying properties, comprise the following steps: judge the vehicle frame load-carrying properties type needing to detect; If vehicle frame load-carrying properties type is maximum shear, then obtains the module of anti-bending section W in maximal bending moment Mmax that monolateral longeron is subject to and longeron cross section, obtain maximum shear according to described maximal bending moment Mmax and module of anti-bending section W wherein, k1 is dynamic load factor, and k2 is endurance ratio; If vehicle frame load-carrying properties type is maximum defluxion, then maximum defluxion ymax=JX/L ³, wherein l is wheelbase, and h is vehicle frame cross section panel height, and b1 is vehicle frame cross-sectional width, and t is vehicle frame section thickness.

Description

A kind of analytical approach of vehicle frame load-carrying properties and device

Technical field

The present invention relates to auto parts and components technical field of performance test, particularly relate to a kind of analytical approach and device of vehicle frame load-carrying properties.

Background technology

Carriage frame is the installation foundation of engine pan, each principal assembly of vehicle body, it is the main load bearing component in vehicle, so the load-carrying properties of vehicle frame (such as strength and stiffness) are analyzed in overall vehicle design very necessary, understanding vehicle frame load-carrying properties in depth is bases that body frame structure for automotive design improves.And in prior art, the check of frame strength and stiffness parameters, relies on personal experience to carry out estimating or utilizes the computing formula of complexity to calculate substantially, very loaded down with trivial details and easily make mistakes, counting yield is low, cumulative errors is large, easily causes function waste.

Summary of the invention

The present invention program's object is: the analytical approach and the device that provide a kind of vehicle frame load-carrying properties, cannot the problem of Measurement accuracy vehicle frame load-carrying properties to solve in prior art.

For this reason, the invention provides a kind of analytical approach of vehicle frame load-carrying properties, comprise the following steps:

Judge the vehicle frame load-carrying properties type needing to detect;

If vehicle frame load-carrying properties type is maximum shear, then

Obtain the module of anti-bending section W in maximal bending moment Mmax that monolateral longeron is subject to and longeron cross section,

Maximum shear σ is obtained according to described maximal bending moment Mmax and module of anti-bending section W wherein, k1 is dynamic load factor, and k2 is endurance ratio;

If vehicle frame load-carrying properties type is maximum defluxion, then

Maximum defluxion ymax=JX/L ³, wherein l is wheelbase, and h is vehicle frame cross section panel height, and b1 is vehicle frame cross-sectional width, and t is vehicle frame section thickness.

Preferably, the maximal bending moment Mmax that the monolateral longeron of described acquisition is subject to is specially:

Obtain the front support reaction FR1 of monolateral longeron, maximal bending moment point x, uniformly distributed load q1 and q2;

According to support reaction FR1 before described monolateral longeron, maximal bending moment point x, uniformly distributed load q1 and q2 calculates $Mmax=\frac{1}{2}\{2FR1*x-\frac{1}{2}q1*{(x+a)}^2-\frac{1}{2}q2*{\[x-(L-C1)\]}^2\};$

Wherein, the front support reaction of monolateral longeron $FR1=\frac{Gs(Lc-2b2)+Ge(C-2C2)}{4L};$

q1＝Gs/Lc；q2＝Ge/C；

$x=\frac{2FR1-q1*a+q2*(L-C1)}{q1+q2}$

Wherein, L is wheelbase, C1 be loading space front end to trailing wheel center line distance from, a is vehicle frame front overhang length, Lc is vehicle frame total length, and b2 is vehicle frame rear overhang length, and C is body length, C2 be loading space rear end to trailing wheel distance between center line, Gs is for reorganizing and outfit spring carried mass, and Ge is container mounted mass.

Preferably, the module of anti-bending section W in described acquisition longeron cross section specifically comprises:

Obtain vehicle frame cross section panel height h, vehicle frame cross-sectional width b1 and vehicle frame section thickness t;

Module of anti-bending section W is obtained according to described vehicle frame cross section panel height h, vehicle frame cross-sectional width b1 and vehicle frame section thickness t:

For beam channel, $W=\frac{1}{6}\×(h+6b1)\×t\×h;$

For rectangular beam: $W=\frac{b1*h^3-(b1-2t){(h-2t)}^3}{6h}.$

Preferably, described judgement also comprises before needing the vehicle frame load-carrying properties type obtained:

Obtain overall dimensions of a car and configuration parameter, vehicle frame cross section parameter and safety coefficient.

The invention provides a kind of analytical equipment of vehicle frame load-carrying properties, comprising:

Judge module, for judging the vehicle frame load-carrying properties type needing to obtain;

Detection module, be connected with described judge module, if be maximum shear for vehicle frame load-carrying properties, then obtain the module of anti-bending section W in maximal bending moment Mmax that monolateral longeron is subject to and longeron cross section, obtain maximum shear according to described maximal bending moment Mmax and module of anti-bending section W wherein, k1 is dynamic load factor, and k2 is endurance ratio; If vehicle frame load-carrying properties are maximum defluxion, then ymax=JX/L ³, wherein

Preferably, described detection module comprises:

Maximal bending moment calculating sub module, for according to support reaction FR1 before described monolateral longeron, maximal bending moment point x, uniformly distributed load q1 and q2 calculates

$Mmax=\frac{1}{2}\{2FR1*x-\frac{1}{2}q1*{(x+a)}^2-\frac{1}{2}q2*{\[x-(L-C1)\]}^2\};$

Wherein, the front support reaction of monolateral longeron $FR1=\frac{Gs(Lc-2b2)+Ge(C-2C2)}{4L};$

q1＝Gs/Lc；q2＝Ge/C；

$x=\frac{2FR1-q1*a+q2*(L-C1)}{q1+q2}$

Wherein, L is wheelbase, C1 be loading space front end to trailing wheel center line distance from, a is vehicle frame front overhang length, Lc is vehicle frame total length, and b2 is vehicle frame rear overhang length, and C is body length, C2 be loading space rear end to trailing wheel distance between center line, Gs is for reorganizing and outfit spring carried mass, and Ge is container mounted mass.

Preferably, described detection module comprises:

Module of anti-bending section calculating sub module, for obtaining module of anti-bending section W according to described vehicle frame cross section panel height h, vehicle frame cross-sectional width b1 and vehicle frame section thickness t:

For beam channel, $W=\frac{1}{6}\×(h+6b1)\×t\×h;$

For rectangular beam: $W=\frac{b1*h^3-(b1-2t){(h-2t)}^3}{6h}.$

Preferably, also comprise parameter acquiring submodule, be connected with described detection module, for obtaining overall dimensions of a car and configuration parameter, vehicle frame cross section parameter and safety coefficient.

Compared with prior art, the present invention has the following advantages:

The present invention, according to the correlation parameter of car load, estimates automatically to vehicle frame load-carrying properties, to check the adaptability of associated technical parameters; Result of calculation can be obtained rapidly, enormously simplify computation process, promote work efficiency and improve accuracy in computation, improving car load cost performance, reducing market failure rate.

Accompanying drawing explanation

Fig. 1 is vehicle frame load-carrying properties analytical approach process flow diagram of the present invention;

Fig. 2 is the whole-car parameters schematic diagram that vehicle frame load-carrying properties of the present invention are analyzed;

Fig. 3 A is the longitudinal beam beam channel schematic diagram that vehicle frame load-carrying properties of the present invention are analyzed;

Fig. 3 B is the longitudinal beam rectangular beam schematic diagram that vehicle frame load-carrying properties of the present invention are analyzed;

Fig. 4 is the vehicle frame force analysis schematic diagram that vehicle frame load-carrying properties of the present invention are analyzed;

Fig. 5 A is the loading diagram that vehicle frame load-carrying properties of the present invention are analyzed;

Fig. 5 B is the stress diagram that vehicle frame load-carrying properties of the present invention are analyzed;

Fig. 5 C is the moment curve that vehicle frame load-carrying properties of the present invention are analyzed.

Embodiment

Be described below in detail embodiments of the invention, the example of described embodiment is shown in the drawings, and wherein same or similar label represents same or similar element or has element that is identical or similar functions from start to finish.Be exemplary below by the embodiment be described with reference to the drawings, be intended to for explaining the present invention, and can not limitation of the present invention be interpreted as.

Below with reference to the accompanying drawings the analytical approach according to vehicle frame load-carrying properties of the present invention and device is described in detail.In order to simplify calculating, following several presupposition is done to whole vehicle model: longeron is the free beam be supported on antero posterior axis; Time unloaded, spring carried mass is distributed in the total length of left and right two longerons, and full load useful load is distributed on body length; All acting forces are all by the flexual center (impact that the local torsion that ignores produces) in cross section.

The analytical approach of vehicle frame load-carrying properties of the present invention as shown in Figure 1, comprises the following steps:

Step 101, obtains overall dimensions of a car and configuration parameter, vehicle frame cross section parameter and safety coefficient.In order to calculate maximum stress in bend σ max and the maximum defluxion ymax of vehicle frame, need clear and definite following parameters.

1. overall dimensions of a car and configuration parameter, as shown in Figure 2: vehicle frame total length Lc (mm), wheelbase L (mm), vehicle frame front overhang a (mm), (mm), body length C (mm), loading space front end to trailing wheel center line C1 (mm), loading space rear end to trailing wheel center line C2 (mm), reorganize and outfit spring carried mass Gs (kg); Mounted mass Ge (kg).

2. vehicle frame cross section parameter: panel height h (mm), width b1 (mm) and thickness t (mm).The longitudinal beam that current cargo vehicle adopts mainly contains beam channel and rectangular beam two kinds, and cross sectional shape is as shown in Fig. 3 A, Fig. 3 B.

3. safety coefficient: consider actual condition, dynamic load factor k1 gets 3 ~ 4.7, and endurance ratio k2 gets 1.4.

Step 102, judges the vehicle frame load-carrying properties type needing to detect, and is need to detect maximum shear, still needs to detect maximum defluxion, or both will detect.

Step 103, brings relevant parameter in step 101 into corresponding formula as required.

If a vehicle frame load-carrying properties type is maximum shear, then obtain the module of anti-bending section W in maximal bending moment Mmax that monolateral longeron is subject to and longeron cross section.

(1) the maximal bending moment Mmax that, the monolateral longeron of described acquisition is subject to is specially:

(1), the front support reaction FR1 of monolateral longeron is obtained, maximal bending moment point x, uniformly distributed load q1 and q2;

(2), according to support reaction FR1 before described monolateral longeron, maximal bending moment point x, uniformly distributed load q1 and q2 calculates $Mmax=\frac{1}{2}\{2FR1*x-\frac{1}{2}q1*{(x+a)}^2-\frac{1}{2}q2*{\[x-(L-C1)\]}^2\};$

The concrete derivation of FR1 is as follows in step (1): vehicle frame force analysis as shown in Figure 4: wherein, the rear support reaction (N) that the front support reaction (N) that FR1 is monolateral longeron, FR2 are monolateral longeron, Gs for reorganizing and outfit spring dead weight capacity (N), Ge is dead weight capacity (N).

Moment is asked to trailing wheel center:

$2FR1\×L-Gs\×(\frac{Lc}{2}-b2)-Ge\×(\frac{C}{2}-C2)=0$

: $FR1=\frac{Gs(Lc-2b2)+Ge(C-2C2)}{4L}$

$FR2=\frac{Gs+Ge-2FR1}{2}$

The concrete derivation of uniformly distributed load q1 and q2 is as follows in step (1): according to force analysis, can make the loading diagram of longeron, stress diagram, moment curve respectively as shown in Fig. 5 A, Fig. 5 B figure, 5C, wherein:

Uniformly distributed load q1=Gs/Lc; Q2=Ge/C;

In step (1), the concrete derivation of maximal bending moment point x is as follows: maximal bending moment point x place, and shear stress is 0:

2FR1-q1×(x+a)-q2×[x-(L-C1)]＝0

: $\begin{array}{c}x=\frac{2FR1-q1*a+q2*(L-C1)}{q1+q2}\\ =\[2FR1-\frac{Gsa}{Lc}+\frac{Ge(L-C1)}{C}\]/(\frac{Gs}{Lc}+\frac{Ge}{C})\end{array}$

(2) the module of anti-bending section W obtaining longeron cross section specifically comprises:

(1) vehicle frame cross section panel height h, vehicle frame cross-sectional width b1 and vehicle frame section thickness t is obtained;

(2) module of anti-bending section W is obtained according to described vehicle frame cross section panel height h, vehicle frame cross-sectional width b1 and vehicle frame section thickness t:

For beam channel as shown in Figure 3A, $W=\frac{1}{6}\×(h+6b1)\×t\×h;$

For rectangular beam as shown in Figure 3 B: $W=\frac{b1*h^3-(b1-2t){(h-2t)}^3}{6h}.$

(3), maximum shear σ is obtained according to described maximal bending moment Mmax and module of anti-bending section W wherein, k1 is dynamic load factor, and k2 is endurance ratio.

If two vehicle frame load-carrying properties types are maximum defluxion, then maximum defluxion wherein l is wheelbase, and h is vehicle frame cross section panel height, and b1 is vehicle frame cross-sectional width, and t is vehicle frame section thickness.

Verify for instantiation below.

Parameter is as follows: vehicle frame total length Lc (mm)=5045; Wheelbase L (mm)=3400; Vehicle frame front overhang a (mm)=700; Vehicle frame rear overhang b2 (mm)=945; Body length C (mm)=3150; Loading space front end is to trailing wheel center line C1 (mm)=1840; Loading space rear end is to trailing wheel center line C2 (mm)=1310; Reorganize and outfit spring carried mass Gs (kg)=2100; Mounted mass Ge (kg)=8500; Section form: beam channel; Panel height h (mm)=232; Width b1 (mm)=60; Thickness t (mm)=9; Dynamic load factor gets 4.7, and endurance ratio gets 1.4;

Result of calculation is as follows: longeron material is 510L, yield strength 295MPa, tensile strength 390-510MPa.

Calculate: σ max=245.4MPa is much smaller than tensile strength, and intensity meets the requirements; $ymax=\frac{JX}{L^3}=60.8>24,$ Rigidity meets the requirements.

The invention provides a kind of analytical equipment of vehicle frame load-carrying properties, comprising:

Judge module, for judging the vehicle frame load-carrying properties type needing to obtain;

Detection module, be connected with described judge module, if be maximum shear for vehicle frame load-carrying properties, then obtain the module of anti-bending section W in maximal bending moment Mmax that monolateral longeron is subject to and longeron cross section, obtain maximum shear according to described maximal bending moment Mmax and module of anti-bending section W wherein, k1 is dynamic load factor, and k2 is endurance ratio; If vehicle frame load-carrying properties are maximum defluxion, then $ymax=\frac{JX}{L3},$ Wherein $JX=\frac{(h+6b1)\×t\×h^2}{12}.$

Described detection module comprises:

Maximal bending moment calculating sub module, for according to support reaction FR1 before described monolateral longeron, maximal bending moment point x, uniformly distributed load q1 and q2 calculates

$Mmax=\frac{1}{2}\{2FRI*x-\frac{1}{2}q1*{(x+a)}^2-\frac{1}{2}q2*{\[x-(L-C1)\]}^2\};$

Wherein, the front support reaction of monolateral longeron $FR1=\frac{Gs(Lc-2b2)+Ge(C-2C2)}{4L};$

q1＝Gs/Lc；q2＝Ge/C；

$x=\frac{2FR1-q1*a+q2*(L-C1)}{q1+q2}$

Wherein, L is wheelbase, C1 be loading space front end to trailing wheel center line distance from, a is vehicle frame front overhang length, Lc is vehicle frame total length, and b2 is vehicle frame rear overhang length, and C is body length, C2 be loading space rear end to trailing wheel distance between center line, Gs is for reorganizing and outfit spring carried mass, and Ge is container mounted mass.

Described detection module comprises:

Module of anti-bending section calculating sub module, for obtaining module of anti-bending section W according to described vehicle frame cross section panel height h, vehicle frame cross-sectional width b1 and vehicle frame section thickness t:

For beam channel, $W=\frac{1}{6}\×(h+6b1)\×t\×h;$

For rectangular beam: $W=\frac{b1*h^3-(b1-2t){(h-2t)}^3}{6h}.$

Also comprise parameter acquiring submodule, be connected with described detection module, for obtaining overall dimensions of a car and configuration parameter, vehicle frame cross section parameter and safety coefficient.

The foregoing is only preferred embodiment of the present invention, be not used for limiting the scope of the invention; Protection scope of the present invention is limited by the claim in claims, and every according to inventing the equivalence change and amendment done, all within the protection domain of patent of the present invention.

Claims (8)

1. an analytical approach for vehicle frame load-carrying properties, is characterized in that, comprises the following steps:

Judge the vehicle frame load-carrying properties type needing to detect;

If vehicle frame load-carrying properties type is maximum shear, then

Obtain the module of anti-bending section W in maximal bending moment Mmax that monolateral longeron is subject to and longeron cross section,

Maximum shear is obtained according to described maximal bending moment Mmax and module of anti-bending section W

wherein, k1 is dynamic load factor, and k2 is endurance ratio;

If vehicle frame load-carrying properties type is maximum defluxion, then

Maximum defluxion ymax=JX/L ³, wherein

l is wheelbase, and h is vehicle frame cross section panel height, and b1 is vehicle frame cross-sectional width, and t is vehicle frame section thickness.

2. the method for claim 1, is characterized in that, the maximal bending moment Mmax that the monolateral longeron of described acquisition is subject to is specially:

Obtain the front support reaction FR1 of monolateral longeron, maximal bending moment point x, uniformly distributed load q1 and q2;

According to support reaction FR1 before described monolateral longeron, maximal bending moment point x, uniformly distributed load q1 and q2 calculates $Mmax=\frac{1}{2}\{2FR1*x-\frac{1}{2}q1*{(x+a)}^2-\frac{1}{2}q2*{\[x-(L-C1)\]}^2\};$

Wherein, the front support reaction of monolateral longeron $FR1=\frac{Gs(Lc-2b2)+Ge(C-2C2)}{4L};$

q1＝Gs/Lc；q2＝Ge/C；

$x=\frac{2FR1-q1*a+q2*(L-C1)}{q1+q2}$

Wherein, L is wheelbase, C1 be loading space front end to trailing wheel center line distance from, a is vehicle frame front overhang length, Lc is vehicle frame total length, and b2 is vehicle frame rear overhang length, and C is body length, C2 be loading space rear end to trailing wheel distance between center line, Gs is for reorganizing and outfit spring carried mass, and Ge is container mounted mass.

3. the method for claim 1, is characterized in that, the module of anti-bending section W in described acquisition longeron cross section specifically comprises:

Obtain vehicle frame cross section panel height h, vehicle frame cross-sectional width b1 and vehicle frame section thickness t;

Module of anti-bending section W is obtained according to described vehicle frame cross section panel height h, vehicle frame cross-sectional width b1 and vehicle frame section thickness t:

For beam channel, $W=\frac{1}{6}\×(h+6b1)\×t\×h;$

For rectangular beam: $W=\frac{b1*h^3-(b1-2t){(h-2t)}^3}{6h}.$

4. the method for claim 1, is characterized in that, described judgement also comprises before needing the vehicle frame load-carrying properties type obtained:

Obtain overall dimensions of a car and configuration parameter, vehicle frame cross section parameter and safety coefficient.

5. an analytical equipment for vehicle frame load-carrying properties, is characterized in that, comprising:

Judge module, for judging the vehicle frame load-carrying properties type needing to obtain;

Detection module, be connected with described judge module, if be maximum shear for vehicle frame load-carrying properties, then obtain the module of anti-bending section W in maximal bending moment Mmax that monolateral longeron is subject to and longeron cross section, obtain maximum shear according to described maximal bending moment Mmax and module of anti-bending section W wherein, k1 is dynamic load factor, and k2 is endurance ratio; If vehicle frame load-carrying properties are maximum defluxion, then maximum defluxion ymax=JX/L ³, wherein l is wheelbase, and h is vehicle frame cross section panel height, and b1 is vehicle frame cross-sectional width, and t is vehicle frame section thickness.

6. the analytical equipment of vehicle frame load-carrying properties as claimed in claim 5, it is characterized in that, described detection module comprises:

Maximal bending moment calculating sub module, for according to support reaction FR1 before described monolateral longeron, maximal bending moment point x, uniformly distributed load q1 and q2 calculates

$Mmax=\frac{1}{2}\{2FR1*x-\frac{1}{2}q1*{(x+a)}^2-\frac{1}{2}q2*{\[x-(L-C1)\]}^2\};$

Wherein, the front support reaction of monolateral longeron $FR1=\frac{Gs(Lc-2b2)+Ge(C-2C2)}{4L};$

q1＝Gs/Lc；q2＝Ge/C；

$x=\frac{2FR1-q1*a+q2*(L-C1)}{q1+q2}$

Wherein, L is wheelbase, C1 be loading space front end to trailing wheel center line distance from, a is vehicle frame front overhang length, Lc is vehicle frame total length, and b2 is vehicle frame rear overhang length, and C is body length, C2 be loading space rear end to trailing wheel distance between center line, Gs is for reorganizing and outfit spring carried mass, and Ge is container mounted mass.

7. the analytical equipment of vehicle frame load-carrying properties as claimed in claim 5, it is characterized in that, described detection module comprises:

Module of anti-bending section calculating sub module, for obtaining module of anti-bending section W according to described vehicle frame cross section panel height h, vehicle frame cross-sectional width b1 and vehicle frame section thickness t:

For beam channel, $W=\frac{1}{6}\×(h+6b1)\×t\×h;$

For rectangular beam: $W=\frac{b1*h^3-(b1-2t){(h-2t)}^3}{6h}.$

8. the analytical equipment of vehicle frame load-carrying properties as claimed in claim 5, is characterized in that, also comprise parameter acquiring submodule, be connected with described detection module, for obtaining overall dimensions of a car and configuration parameter, vehicle frame cross section parameter and safety coefficient.