CN101470057A - Evaluation method for critical stress and platform stress of honeycomb paper sheet - Google Patents

Abstract

The invention relates to an evaluation method for critical stress and plateau stress of honeycomb paperboard, belonging to the performance detection field of honeycomb paperboard. The detection method adopts a measurement device to measure the thickness t of a honeycomb fiberboard medium, the edge length I of honeycomb pores, the elastic modulus Es, the poisson ratio vs and the flexing stress of the honeycomb fiberboard medium and the like; utilizes critical stress detection method and plateau stress evaluation method to process detection and calculation. The invention adopts the evaluation method on the critical stress and plateau stress of honeycomb paperboard to test the data relative to honeycomb paperboard, therefore, obtained relative detection data is accurate and the evaluation method is simple and fast. The evaluation method provides basis for the manufacture, material selection and structure design of honeycomb paperboards.

Description

A kind of honeycomb cardboard limit stress and platform stress evaluation method

Technical field

The invention belongs to honeycomb cardboard Performance Detection field, relate to a kind of honeycomb cardboard limit stress and platform stress evaluation method.

Background technology

Along with Chinese economic development, the increase of trade in order to alleviate the pressure of China's timber shortage, reduces logistics cost, and is increasing to the demand of cellular carton and honeycomb paperboard tray in recent years.Honeycomb cardboard is applied among the transportation and packing as dividing plate or loading plate usually, it can also be used to make the paper pallet, to replace the wooden block dish, because Wooden tray needs to fumigate processing in the transportation of passing by, to kill the insect pest that may be present in the Wooden tray, can influence the quality of the goods of Wooden tray stored like this.

Honeycomb cardboard is used for dividing plate or the paper pallet mainly is because honeycomb cardboard has higher static load-carrying properties.The quasistatic pressure-bearing process of honeycomb cardboard can be divided into four-stage: linear elasticity stage, elastic-plastic phase, plasticity are caved in stage and densification stage, and its compression stress strain law curve as shown in Figure 1.The stress point that has a key on its compression stress strain curve for the stress plateau section of a some B and a key, is line segment CD in the drawings in the drawings.The critical stress point is the limit stress point in the effective compression zone of honeycomb cardboard, and this stress point can be assessed the maximum load performance of honeycomb cardboard; Critical stress platform section is the platform stress in the effective compression zone of honeycomb cardboard, and the size of this stress value has determined the size of honeycomb cardboard maximum distortion energy to a great extent, has determined the shock-absorbing capacity of honeycomb cardboard.

The static load-carrying properties of honeycomb cardboard still are in the experimental study stage at present, wonder the static load-carrying properties of a certain honeycomb cardboard, this honeycomb cardboard of need making carries out the quasistatic compression test again and obtains, and, make that the kind of honeycomb cardboard is very many along with the variation of honeycomb pore size, the variation of honeycomb body paper.It almost is impossible that the static load-carrying properties of wondering certain honeycomb cardboard rely on research technique merely.So now the judgement for the static load-carrying properties of honeycomb cardboard does not have better foundation on the market, can only rule of thumb estimate.So static load-carrying properties how to predict honeycomb cardboard are problems that honeycomb cardboard production and use both sides are concerned about very much.

Summary of the invention

There is not reliable foundation in order to solve the assessment that exists in the prior art for honeycomb cardboard limit stress and platform stress, can only rule of thumb estimate or just can obtain through a large amount of tests, experience estimation numerical value is inaccurate, obtain series of technical such as mathematical program is loaded down with trivial details through a large amount of tests, the invention provides a kind of honeycomb cardboard limit stress and platform stress evaluation method.

The present invention solves technical scheme that the prior art problem adopted for a kind of honeycomb cardboard limit stress appraisal procedure is provided, and described honeycomb cardboard limit stress appraisal procedure comprises step: the thickness t, the length of side 1 of honeycomb hole and the stretching angle θ of honeycomb that the first, measure the honeycomb body paper by measurement mechanism; The second, detect the elastic modulus E of honeycomb body paper by pick-up unit _sPoisson ratio ν with the honeycomb body paper _sThree, according to formula ${{\mathrm{\σ}}_3}^{*}=\frac{7.7E_s}{(1-v_s)\cos \mathrm{\θ}(1+\sin \mathrm{\θ})}{\left(\frac{t}{l}\right)}^3,$ Obtain honeycomb cardboard limit stress assessed value σ ₃ ^*

According to a preferred embodiment of the invention: described honeycomb cardboard limit stress appraisal procedure comprises step: the elastic modulus E that the first, detects the honeycomb body paper by pick-up unit _sPoisson ratio v with the honeycomb body paper _sThe second, measure thickness t, the length of side 1 of honeycomb hole and the stretching angle θ of honeycomb of honeycomb body paper by measurement mechanism; Three, according to formula ${{\mathrm{\σ}}_3}^{*}=\frac{7.7E_s}{(1-v_s)\cos \mathrm{\θ}(1+\sin \mathrm{\θ})}{\left(\frac{t}{l}\right)}^3,$ Obtain honeycomb cardboard limit stress assessed value σ ₃ ^*

Above-mentioned detection order to the detection data can be in no particular order.

The present invention solves technical scheme that the prior art problem adopted for a kind of honeycomb cardboard platform stress evaluation method is provided, and described honeycomb cardboard platform stress evaluation method comprises step: the first, measure the thickness t of honeycomb body paper, the length of side 1 of honeycomb hole by measurement mechanism; The second, detect the yield stress σ of honeycomb body paper by pick-up unit _YsThree, according to formula ${\mathrm{\σ}}_{p1}=13.2{\mathrm{\σ}}_{\mathrm{ys}}{\left(\frac{t}{l}\right)}^{1.77},$ Obtain honeycomb cardboard platform stress evaluation value σ _Pl

According to a preferred embodiment of the invention: described honeycomb cardboard platform stress evaluation method comprises step: the yield stress σ that the first, detects the honeycomb body paper by pick-up unit _YsThe second, measure the thickness t of honeycomb body paper, the length of side 1 of honeycomb hole by measurement mechanism; Three, according to formula ${\mathrm{\σ}}_{p1}=13.2{\mathrm{\σ}}_{\mathrm{ys}}{\left(\frac{t}{l}\right)}^{1.77},$ Obtain honeycomb cardboard platform stress evaluation value σ _Pl

Above-mentioned detection order to the detection data can be in no particular order.

Beneficial effect of the present invention is: by honeycomb cardboard limit stress and platform stress evaluation method the related data of honeycomb cardboard is calculated, is made resulting coherent detection data accurate, and appraisal procedure subtracts just, fast.For the making selection and the structural design of honeycomb cardboard provides foundation.

Description of drawings

Fig. 1. honeycomb cardboard quasistatic compression stress strain curve rule synoptic diagram in the prior art;

Fig. 2. the paper honeycomb structure synoptic diagram.

Embodiment

The invention will be further described below in conjunction with drawings and Examples:

See also Fig. 1. honeycomb cardboard quasistatic compression stress strain curve rule synoptic diagram in the prior art, the quasistatic pressure-bearing process of honeycomb cardboard can be divided into four-stage: linear elasticity stage, elastic-plastic phase, plasticity are caved in stage and densification stage, and its compression stress strain law curve as shown in Figure 1.On its compression stress strain curve, there are a stress point-B of a key and the stress plateau section-line segment CD of a key.The critical stress point is the limit stress point in the effective compression zone of honeycomb cardboard, and this stress point can be assessed the maximum load performance of honeycomb cardboard; Critical stress platform section is the platform stress in the effective compression zone of honeycomb cardboard, and the size of this stress value has determined the size of honeycomb cardboard maximum distortion energy to a great extent, has determined the shock-absorbing capacity of honeycomb cardboard.

Honeycomb cardboard is pasted facial tissue up and down by the sexangle paper honeycomb core usually and is formed, and the structural parameters of sexangle paper honeycomb core can be consulted Fig. 2 paper honeycomb structure synoptic diagram.

The load performance of honeycomb cardboard is mainly by the structure of paper honeycomb core and the proper property decision of honeycomb body paper, and for Type B paper honeycomb core commonly used, the limit stress of honeycomb cardboard assessment equation is:

${{\mathrm{\σ}}_3}^{*}=\frac{7.7E_s}{(1-v_s)\cos \mathrm{\θ}(1+\sin \mathrm{\θ})}{\left(\frac{t}{l}\right)}^3---\left(1\right)$

In formula (1), each parameter-definition as shown in Figure 2: σ ₃ ^*-honeycomb cardboard compression limit stress; The elastic modulus of Es-honeycomb body paper; The thickness of t-honeycomb body paper; The length of side of 1-honeycomb hole; The stretching angle of θ-paper wasp nest; v _sThe Poisson ratio of-honeycomb body paper.

The platform stress evaluation equation of honeycomb cardboard is:

${\mathrm{\σ}}_{p1}=13.2{\mathrm{\σ}}_{\mathrm{ys}}{\left(\frac{t}{l}\right)}^{1.77}---\left(2\right)$

In formula (2), each parameter-definition is as follows: σ _PlThe compressed platform stress of-honeycomb body paper; σ _YsThe buckling stress of-honeycomb body paper; The thickness of t-honeycomb body paper; The length of side of 1-honeycomb hole;

For the honeycomb body paper of papery of the same race, the length of side that increases the thickness of honeycomb body paper or reduce the paper wasp nest all can make the load performance of honeycomb cardboard improve.E in formula (1) and the formula (2) _sAnd σ _YsBy the characteristic decision of honeycomb body paper, these two parameters all can be provided by honeycomb body paper manufacturer.

Above content be in conjunction with concrete preferred implementation to further describing that the present invention did, can not assert that concrete enforcement of the present invention is confined to these explanations.For the general technical staff of the technical field of the invention, without departing from the inventive concept of the premise, can also make some simple deduction or replace, all should be considered as belonging to protection scope of the present invention.

Claims (4)

1. honeycomb cardboard limit stress appraisal procedure, it is characterized in that: described honeycomb cardboard limit stress appraisal procedure comprises step:

A: the thickness t, the length of side 1 of honeycomb hole and the stretching angle θ of honeycomb that measure the honeycomb body paper by measurement mechanism;

B: the elastic modulus E that detects the honeycomb body paper by pick-up unit _sPoisson ratio v with the honeycomb body paper _s

C: according to formula ${{\mathrm{\σ}}_3}^{*}=\frac{7.7E_s}{(1-v_s)\cos \mathrm{\θ}(1+\sin \mathrm{\θ})}{\left(\frac{t}{l}\right)}^3,$ Obtain honeycomb cardboard limit stress assessed value σ ₃ ^*

2. according to the described honeycomb cardboard limit stress of claim 1 appraisal procedure, it is characterized in that: described honeycomb cardboard limit stress appraisal procedure comprises step:

A: the elastic modulus E that detects the honeycomb body paper by pick-up unit _sPoisson ratio v with the honeycomb body paper _s

B: the thickness t, the length of side 1 of honeycomb hole and the stretching angle θ of honeycomb that measure the honeycomb body paper by measurement mechanism;

C: according to formula ${{\mathrm{\σ}}_3}^{*}=\frac{7.7E_s}{(1-v_s)\cos \mathrm{\θ}(1+\sin \mathrm{\θ})}{\left(\frac{t}{l}\right)}^3,$ Obtain honeycomb cardboard limit stress assessed value σ ₃ ^*

3. honeycomb cardboard platform stress evaluation method, it is characterized in that: described honeycomb cardboard platform stress evaluation method comprises step:

D: measure the thickness t of honeycomb body paper, the length of side 1 of honeycomb hole by measurement mechanism;

E: the buckling stress σ that detects the honeycomb body paper by pick-up unit _Ys

F: according to formula ${\mathrm{\σ}}_{p1}=13.2{\mathrm{\σ}}_{\mathrm{ys}}{\left(\frac{t}{l}\right)}^{1.77},$ Obtain honeycomb cardboard platform stress evaluation value σ _Pl

4. according to the described honeycomb cardboard platform of claim 3 stress evaluation method, it is characterized in that: described honeycomb cardboard platform stress evaluation method comprises step:

D: the buckling stress σ that detects the honeycomb body paper by pick-up unit _Ys

E: measure the thickness t of honeycomb body paper, the length of side 1 of honeycomb hole by measurement mechanism;

F: according to formula ${\mathrm{\σ}}_{p1}=13.2{\mathrm{\σ}}_{\mathrm{ys}}{\left(\frac{t}{l}\right)}^{1.77},$ Obtain honeycomb cardboard platform stress evaluation value σ _Pl

Images