CN105512791A - Method for assessing personal casualty losses caused by failed lightning protection device - Google Patents

Abstract

The invention relates to a method for assessing personal casualty losses caused by a failed lightning protection device. The method comprises the steps of 1) determining events in a fault tree; 2) establishing a fault tree of personal casualty losses in a lightning protection system of a building through a logic gate circuit of an AND gate or an OR gate; 3) listing a boolean expression according to a constructed chart of the fault tree, obtaining a minimum cut set and a minimum path set, and determining the structural importance of each basic event; 4) performing a quantitative analysis of the probability of the occurrence of the top events based on the theory of fuzzy mathematics by using an analytical approach of a triangular fuzzy fault tree; and 5) conducting a fuzzy importance analysis, giving system security analysis suggestions, and working out fault preventing measures. The invention has the beneficial effects of enhancing the awareness of reasonable and effective installation of a lightning protection device and preventing both natural disasters and man-made disasters through the fuzzy fault tree analysis of the personal casualty losses resulted from failed lightning protection device of the building.

Description

A kind of thunderstorm electricity protective device that lost efficacy causes the method for personal injury loss appraisal

Technical field

The invention belongs to Lightning Disaster risk assessment field, particularly relate to a kind of method that thunderstorm electricity protective device that lost efficacy causes personal injury loss appraisal.

Background technology

The society level of economic development is more and more higher, and people also more and more pay attention to the harm that thunder and lightning brings, and buildings generally installs thunderstorm electricity protective device.But thunderstorm electricity protective device is not absolutely to the protection effect of thunder and lightning, installation improperly or the thunderstorm electricity protective device lost efficacy can grow new harm on the contrary, and personal injury even can be caused to lose.In order to more reasonably take lightning protection measures, avoiding installation blindly, needing to cause personal injury loss to be assessed to inefficacy thunderstorm electricity protective device.

Fault tree analysis process (FTA) is a kind of method for Complex System Reliability, safety prediction.Event tree least wishes event with system---top event is evaluating objects, the various direct and remote cause that the technique study that applied logic is deduced causes top event to occur, and with " logic gate ", a variety of causes is associated, set up a tree-shaped figure stood upside down, and point out the logical communication link between cell failure and the system failure, applied probability statistical method carries out qualitative and quantitative analysis, can seek the minimal cut set that top event occurs, the probability that minimum path sets and top event occur.

Event tree analysis is placed on the top of figure contingent for system accident, is called top event, by the relation between System Forming Elements, analyzes the reason relevant with disaster accident.These reasons, may be the result of some other reason, be called middle reason event (or intermediate event), should continue down to analyze, until find out the reason that can not down analyze further, these reasons are called fundamental cause event (or elementary event).In figure, the different logic gate of each cause-effect relationship links up, the figure image inverted tree obtained like this.

Fault tree analysis process can identify the elementary event causing accident, and in addition comprehensively, succinct and vividly describe, carry out qualitative and quantitative analysis and system evaluation.If but lacking corresponding data, then qualitative assessment is comparatively difficult.In addition, also cannot analyze ambiguity event.Fuzzy fault tree analysis (FFTA) method is arisen at the historic moment.Fuzzy event tree is that event tree and Fuzzy Set Theory are combined, by all event tree node obfuscations, represent the degree that fuzzy event occurs namely to each fuzzy event definition subordinate function, qualitative and quantitative analysis is carried out to event tree, for the top event of event tree and the probability of happening of bottom event, fuzzy probability is adopted to replace accurate probable value.

Below by way of the relevant last word of research and utility model patent, further illustrate technical background of the present invention.Patent-a kind of Mond process of applying carries out the method (201410125342) of fire explosion risk assessment by asking for the size of each fire explosion risk elementary event structure importance, determine its when using Mond process to carry out safety evaluation in " suggestion coefficient " scope the value size issue of " employing coefficient ".The method is for calculating chemical industry fire explosion risk, belonging to different application field with the inventive method.Patent-a kind of electrical system method for evaluating reliability (20131002926) based on the fuzzy event tree of binary carries out the problem of reliability evaluation for the polynary influence factor of use and fuzzy evaluation data to electrical system, selects working time and the reliability of working temperature to each element and composition system thereof to determine.The reason lost efficacy due to thunderstorm electricity protective device has many, and influence degree is uncertain, can not assess polynary influence factor, therefore the method is not suitable for the risk assessment of inefficacy thunderstorm electricity protective device.

Summary of the invention

The object of the invention is to overcome above prior art thunderstorm electricity protective device Rig up error or inefficacy causes buildings once be struck by lightning, protective device performs practically no function, very easily lead to disaster, even can cause the deficiency that personal injury loses, event tree analysis is carried out by the hazard approach causing personal injury to lose to buildings inefficacy thunderstorm electricity protective device, find out the safe weak link of buildings thunderstorm electricity protective device, there is provided a kind of thunderstorm electricity protective device that lost efficacy to cause the method for personal injury loss appraisal, specifically have following technical scheme to realize:

Described inefficacy thunderstorm electricity protective device causes the method for personal injury loss appraisal, comprises the steps:

1) event in event tree is established;

2) by setting up with the logic gates of door or door the event tree that in buildings lightning protection system, personal injury loses;

3) according to the accident tree graph constructed, list Boolean expression, obtain minimal cut set, minimum path sets, determine the structure importance of each elementary event;

4) according to fuzzy mathematics theory, adopt the analytical approach of the fuzzy event tree of triangle, quantitative test is carried out to the probability of the generation of top event;

5) carry out Fuzzy importance analysis, provide System Safety Analysis suggestion, formulate preventive damage control.

Described inefficacy thunderstorm electricity protective device causes the further design of the method for personal injury loss appraisal to be, described step 1) comprise the steps:

1-1) determine top event, set top event as " personal injury loss ";

1-2) by the relation between System Forming Elements, analyze the reason relevant with disaster accident;

1-3) investigation accident, analysis reason.

Described inefficacy thunderstorm electricity protective device causes the further design of the method for personal injury loss appraisal to be, described step 1-3) in, if through step 1-2) as long as the reason analyzing the disaster accident that obtains relevant has any one to occur, top event will occur, and is connected by described reason logic sum gate;

If through step 1-2) reason of analyzing the disaster accident that obtains relevant needs to occur simultaneously, and top event just can occur, and is connected by described reason logical AND gate.

Described inefficacy thunderstorm electricity protective device causes the further design of the method for personal injury loss appraisal to be, described step 4) comprise the steps:

4-1) obtain the probability that elementary event occurs, for the elementary event being obtained accident rate by reliability handbook, empirical data, according to the probability of happening of accident rate, probability distribution parameters acquisition elementary event;

4-2) by step 4-1) probability of happening of elementary event that obtains, by described probability of happening, it is normalized to the fuzzy number of triangular form;

4-3) utilize with or fuzzy operator try to achieve the fuzzy probability that top event occurs.

Described inefficacy thunderstorm electricity protective device causes the further design of the method for personal injury loss appraisal to be, the probability of happening of described elementary event comprises various ways, is respectively: exact value, Linguistic Value and fuzzy number.

Described inefficacy thunderstorm electricity protective device causes the further design of the method for personal injury loss appraisal to be, described step 4-2) in, triangle Fuzzy Distribution is denoted as (l, m, u):

For the normalized of the probable value of exact value form, by exact probability value p, changing into Triangular Fuzzy Number is u=(p, p, p);

For the normalized of the probable value of Linguistic Value form, determine the magnitude of probability corresponding to Linguistic Value, using the m value of this magnitude as corresponding language value, then be translated into Triangular Fuzzy Number (a, m, b), m-a=b-m=0.0556m;

For the normalized of the probable value of other forms of non-triangle fuzzy number, first obtain the center of gravity of subordinate function corresponding to described probable value as m, then become Triangular Fuzzy Number (a, m, b), wherein a, the relation of m, b is shown below: m-a=b-m=0.0556m.

Described inefficacy thunderstorm electricity protective device causes the further design of the method for personal injury loss appraisal to be, described step 4-3) in, the fuzzy operator formula with door, shown in (1),

${\tilde{q}}_{AND}={\tilde{q}}_1\⊗{\tilde{q}}_2\⊗{\tilde{q}}_3...\⊗{\tilde{q}}_n=\left(\underset{i=1}{\overset{n}{\Π}}{l}_i,\underset{i=1}{\overset{n}{\Π}}{m}_i,\underset{i=1}{\overset{n}{\Π}}{u}_i\right)---\left(1\right)$

The operator formula of fuzzy or door, shown in (2),

${\tilde{q}}_{OR}=\left(1-\left(1-\underset{i=1}{\overset{n}{\Π}}{l}_i\right),1-\left(1-\underset{i=1}{\overset{n}{\Π}}{m}_i\right),1-\left(1-\underset{i=1}{\overset{n}{\Π}}{u}_i\right)\right)---\left(2\right).$

Described inefficacy thunderstorm electricity protective device causes the further design of the method for personal injury loss appraisal to be, described step 5) in, the structure function of setting event tree is Φ (X ₁, X ₂..., X _n), wherein X _ievent tree elementary event, X _ipossibility distrabtion Triangular Fuzzy Number form provide, be designated as the possibility distrabtion of top event is: $\widetilde{\mathrm{\&Phi;}}({\tilde{X}}_1,\widetilde{X_2},...,\widetilde{X_n})=<l,m,u>,$ Median is designated as T _z.

Wherein: $T_z=\left\{\begin{array}{c}m+\sqrt{u^2-ul},u>1\\ m-\sqrt{l^2-ul},u<1\end{array}\right.,$ The possibility distrabtion of elementary event is:

its median is designated as T _zi.Elementary event X _ifuzzy importance S _i=T _z-T _ziif, S _i> S _j, then pay the utmost attention to and improve elementary event X _iimprove the reliability of system.

Advantage of the present invention is as follows:

The advantage making full use of fault tree analysis process and fuzzy mathematics combines, and the assessment of the personal injury that carries out loss can overcome when using separately event tree to evaluate, and decreases the uncertainty of probability of occurrence in event tree, has more practical value.By to buildings inefficacy thunderstorm electricity protective device personal injury loss fuzzy fault tree analysis, strengthen people to the consciousness of rationally effectively carrying out thunderstorm electricity protective device installation, prevent natural disaster from more preventing man-made calamity.

Accompanying drawing explanation

A kind of involved by the present invention of Fig. 1 applies fuzzy event tree and carries out inefficacy thunderstorm electricity protective device and cause event tree event notation schematic diagram in the method for personal injury loss appraisal.

A kind of involved by the present invention of Fig. 2 applies fuzzy event tree and carries out inefficacy thunderstorm electricity protective device and cause fuzzy event tree establishment step schematic diagram in the method for personal injury loss appraisal.

A kind of involved by the present invention of Fig. 3 applies fuzzy event tree and carries out the subordinate function schematic diagram that inefficacy thunderstorm electricity protective device causes the method intermediate cam fuzzy number of personal injury loss appraisal.

A kind of involved by the present invention of Fig. 4 applies fuzzy event tree and carries out inefficacy thunderstorm electricity protective device and cause event tree in the method for personal injury loss appraisal.

Embodiment

Below in conjunction with accompanying drawing, the present invention program is described in detail.

The inefficacy thunderstorm electricity protective device of the present embodiment causes the method for personal injury loss appraisal, and step is as follows:

1, the establishment of event in event tree, step is as follows:

1-1) determine top event, top event is " personal injury loss " (event tree the 1st layer).

1-2) by the relation between System Forming Elements, analyze the reason relevant with disaster accident.

1-3) investigation accident, analysis reason.

Further, the reason logical relation of accident is as follows: the logical relation (event tree the 2nd layer) of investigation " top event " and " middle reason event ".Middle reason event " electric shock injures and deaths " and " fire injures and deaths ", as long as these two events have a generation, " top event " will occur, so connect with logic sum gate.

" middle reason event " and the logical relation thereof (event tree the 3rd layer) of investigation event tree the 3rd layer of event, for " electric shock injures and deaths " event analysis, " middle reason event ": " personnel are excessively near apart from the outer downlead of buildings " and " touch voltage and step voltage " these two events, only have and occur just to cause personnel to get an electric shock simultaneously, so use logical AND gate to connect.

" middle reason event " and the logical relation thereof (event tree the 4th layer) of investigation event tree the 4th layer of event, " the middle reason event " of " touch voltage and step voltage ": " around downlead, topsoil resistivity is too small ", " downlead earial drainage fault " " inefficacy of grounding terminals equipotential bonding " these three events occur arbitrarily one and all can cause " touch voltage and step voltage ", thus with or door connect.The reason of " personnel are excessively near apart from the outer downlead of buildings ": " safe distance is too small " or " warning mark inefficacy ", so connect with logic sum gate.

" middle reason event " and the logical relation thereof (event tree the 5th layer) " downlead earial drainage fault " of investigation event tree the 5th layer of event may be cause, so connect with logic sum gate because of " electrical continuity of downlead destroys ", " construction and installation of bright dress downlead are undesirable " or " failure of insulation of downlead "." cautionary measure inefficacy " may " alarming device destruction " or " not establishing alarming device " cause, so connect with logic sum gate.

" middle reason event " and the logical relation thereof (event tree the 6th layer) of investigation event tree the 6th layer of event, " failure of insulation of downlead " is caused, so connect with logical AND gate by " insulation ag(e)ing " and " Maintenance and Repair are not in place " simultaneously.

" middle reason event " and the logical relation thereof (event tree the 7th layer) of investigation event tree the 7th layer of event, " insulation ag(e)ing " is caused, so connect with logic sum gate by " environmental corrosion " or " insulating material is undesirable ").

2, construct event tree, and by be not with the logic gate of door be converted into or door.According to above-mentioned analytical approach, set up the event tree of personal injury loss in buildings lightning protection system.

3, qualitative analysis

According to the accident tree graph constructed, as shown in table 1, list Boolean expression, obtain minimal cut set, minimum path sets, determine the structure importance of each elementary event.

The list of table 1 elementary event

The Boolean expression of event tree:

(X1+X2+X3)*(X4+X5+X6+X7+X8*(X9+X10))+(X11+X12+X13+X14)*(X15+X16+X6+X7+X8*X9*X10+X17+X18)*(X19+X20+X21+X22+X23+X8*(X9+X10))

In event tree, when all events do not occur, top event can not occur certainly.But top event does not occur usually not require that all elementary events do not occur, as long as and there is not top event and just not occur in some elementary event.The set of these elementary events do not occurred is called footpath collection.In same event tree, the footpath not comprising other footpath collection integrates as minimum path sets.Minimum path sets is the sufficient and necessary condition ensureing that top event does not occur.Minimum path sets:

(X1*X2*X3*X6*X7*X8*X15*X16*X17*X18)；

(X1*X2*X3*X6*X7*X9*X15*X16*X17*X18)；

(X1*X2*X3*X6*X7*X10*X15*X16*X17*X18)；

(X1*X2*X3*X8*X19*X20*X21*X22*X23)；

(X1*X2*X3*X9*X10*X19*X20*X21*X22*X23)；(X1*X2*X3*X11*X12*X13*X14)

(X4*X5*X6*X7*X8*X9*X10*X15*X16*X17*X18)；

(X4*X5*X6*X7*X8*X9*X10*X19*X20*X21*X22*X23)；

(X4*X5*X6*X7*X8*X9*X15*X16*X17*X18)；

(X4*X5*X6*X7*X8*X10*X15*X16*X17*X18)；

(X4*X5*X6*X7*X8*X11*X12*X13*X14)；(X4*X5*X6*X7*X8*X15*X16*X17*X18)；

(X4*X5*X6*X7*X8*X19*X20*X21*X22*X23)；

(X4*X5*X6*X7*X9*X10*X11*X12*X13*X14)；

(X4*X5*X6*X7*X9*X10*X15*X16*X17*X18)；

(X4*X5*X6*X7*X9*X10*X19*X20*X21*X22*X23)；

Structure importance is the degree that the generation of balance each " elementary event " makes a difference to " top event ", and the initial reason caused the accident is a lot, when taking measures, should according to the order of importance and emergency, and preferential those sixty-four dollar questions of solution.Structure importance:

I(X3)＝I(X2)＝I(X1)>I(X7)＝I(X6)>I(X14)＝I(X13)＝I(X12)＝I(X11)>I(X8)>I(X5)＝I(X4)>I(X18)＝I(X17)＝I(X16)＝I(X15)>I(X10)＝I(X9)>I(X23)＝I(X22)＝I(X21)＝I(X20)＝I(X19)

By the analysis to elementary event structure importance, find to need to strengthen buildings thunderstorm electricity protective device prophylactic repair and maintenance measure, strengthen isolating and warning measure.

4, quantitative test

The object of quantitative test is the probability of the generation obtaining " top event " and itself and the desired value determined is contrasted.Due to reasons such as the insufficiency of secure data and the ambiguities of elementary event, the exact method of elementary event cannot be provided.Therefore, introduce fuzzy mathematics theory, think that the probability of happening of these elementary events is fuzzy numbers, adopt the analytical approach of the fuzzy event tree of triangle, carry out quantitative test.Concrete steps are as follows:

(1) probability that elementary event occurs is obtained

For the elementary event that can be obtained accident rate by approach such as reliability handbook, empirical datas, according to the probability of happening of accident rate, probability distribution parameters and other gain of parameter elementary events, this is exact value.For the elementary event and other fuzzy events that there is no statistics, preset fuzzy probability of happening, various fuzzy number and Linguistic Value evaluation can be adopted.

(2) normalization of fuzzy number

The probability of happening of the elementary event obtained by above approach may be various ways, comprises exact value, Linguistic Value and various fuzzy number, is normalized to the fuzzy number of triangular form.

As shown in Figure 3, give the schematic diagram of triangle Fuzzy Distribution, be denoted as for exact probability value p, changing into Triangular Fuzzy Number is u=(p, p, p); For other forms of non-triangle fuzzy number, as Normal Fuzzy-number, first obtain the center of gravity of corresponding subordinate function as m, then become Triangular Fuzzy Number (a, m, b), wherein the relation of a, m, b is shown below: m-a=b-m=0.0556m; For Linguistic Value, first understand the roughly magnitude of probability corresponding to Linguistic Value, using the m value of this magnitude as corresponding language value, then be translated into Triangular Fuzzy Number (a, m, b), m-a=b-m=0.0556m.

(3) utilize with or fuzzy operator try to achieve the fuzzy probability that top event occurs;

The fuzzy operator formula with door:

${\tilde{q}}_{AND}={\tilde{q}}_1\&CircleTimes;{\tilde{q}}_2\&CircleTimes;{\tilde{q}}_3...\&CircleTimes;{\tilde{q}}_n=\left(\underset{i=1}{\overset{n}{\&Pi;}}{l}_i,\underset{i=1}{\overset{n}{\&Pi;}}{m}_i,\underset{i=1}{\overset{n}{\&Pi;}}{u}_i\right)$

The operator formula of fuzzy or door:

${\tilde{q}}_{OR}=\left(1-\left(1-\underset{i=1}{\overset{n}{\&Pi;}}{l}_i\right),1-\left(1-\underset{i=1}{\overset{n}{\&Pi;}}{m}_i\right),1-\left(1-\underset{i=1}{\overset{n}{\&Pi;}}{u}_i\right)\right)$

5, carry out Fuzzy importance analysis, provide System Safety Analysis suggestion, formulate preventive damage control

If the structure function of event tree is Φ (X ₁, X ₂..., X _n), wherein X _ibe event tree elementary event, its possibility distrabtion Triangular Fuzzy Number form provides, and is designated as then the possibility distrabtion of top event is: $\widetilde{\mathrm{\&Phi;}}({\tilde{X}}_1,\widetilde{X_2},...,\widetilde{X_n})=<l,m,u>,$ Median is designated as T _z.

Wherein: $T_z=\left\{\begin{array}{c}m+\sqrt{u^2-ul},u>1\\ m-\sqrt{l^2-ul},u<1\end{array}\right..$

The possibility distrabtion of elementary event is: median is designated as T _zi.Elementary event X _ifuzzy importance S _i=T _z-T _ziif, S _i> S _j, then S is thought _icompare S _jimportant, large on the impact of system, should first consider to improve elementary event X _iimprove the reliability of system.

Claims (8)

1. the thunderstorm electricity protective device that lost efficacy causes a method for personal injury loss appraisal, it is characterized in that comprising the steps:

1) event in event tree is established;

2) by setting up with the logic gates of door or door the event tree that in buildings lightning protection system, personal injury loses;

3) according to the accident tree graph constructed, list Boolean expression, obtain minimal cut set, minimum path sets, determine the structure importance of each elementary event;

4) according to fuzzy mathematics theory, adopt the analytical approach of the fuzzy event tree of triangle, quantitative test is carried out to the probability of the generation of top event;

5) carry out Fuzzy importance analysis, provide System Safety Analysis suggestion, formulate preventive damage control.

2. inefficacy thunderstorm electricity protective device according to claim 1 causes the method for personal injury loss appraisal, it is characterized in that described step 1) comprise the steps:

1-1) determine top event, set top event as " personal injury loss ";

1-2) by the relation between System Forming Elements, analyze the reason relevant with disaster accident;

1-3) investigation accident, analysis reason.

3. inefficacy thunderstorm electricity protective device according to claim 2 causes the method for personal injury loss appraisal, it is characterized in that described step 1-3) in, if through step 1-2) as long as the reason analyzing the disaster accident that obtains relevant has any one to occur, top event will occur, and is connected by described reason logic sum gate;

If through step 1-2) reason of analyzing the disaster accident that obtains relevant needs to occur simultaneously, and top event just can occur, and is connected by described reason logical AND gate.

4. inefficacy thunderstorm electricity protective device according to claim 1 causes the method for personal injury loss appraisal, it is characterized in that described step 4) comprise the steps:

4-1) obtain the probability that elementary event occurs, for the elementary event being obtained accident rate by reliability handbook, empirical data, according to the probability of happening of accident rate, probability distribution parameters acquisition elementary event;

4-2) by step 4-1) probability of happening of elementary event that obtains, by described probability of happening, it is normalized to the fuzzy number of triangular form;

4-3) utilize with or fuzzy operator try to achieve the fuzzy probability that top event occurs.

5. inefficacy thunderstorm electricity protective device according to claim 4 causes the method for personal injury loss appraisal, it is characterized in that the probability of happening of described elementary event comprises various ways, is respectively: exact value, Linguistic Value and fuzzy number.

6. inefficacy thunderstorm electricity protective device according to claim 5 causes the method for personal injury loss appraisal, it is characterized in that described step 4-2) in, triangle Fuzzy Distribution M is denoted as (l, m, u), m is the degree of membership of M is the intermediate value of 1, as x=m, x belongs to M completely, l and u is respectively lower bound and the upper bound, beyond l and u, do not belong to fuzzy number M completely.

For the normalized of the probable value of exact value form, by exact probability value p, changing into Triangular Fuzzy Number is u=(p, p, p);

For the normalized of the probable value of Linguistic Value form, determine the magnitude of probability corresponding to Linguistic Value, using the m value of this magnitude as corresponding language value, then be translated into Triangular Fuzzy Number (a, m, b), m-a=b-m=0.0556m;

For the normalized of the probable value of other forms of non-triangle fuzzy number, first obtain the center of gravity of subordinate function corresponding to described probable value as m, then become Triangular Fuzzy Number (a, m, b), wherein a, the relation of m, b is shown below: m-a=b-m=0.0556m.

7. inefficacy thunderstorm electricity protective device according to claim 4 causes the method for personal injury loss appraisal, it is characterized in that described step 4-3) in, the fuzzy operator formula with door, shown in (1),

The operator formula of fuzzy or door, shown in (2),

${\tilde{q}}_{OR}=(1-(1-\underset{i=1}{\overset{n}{\&Pi;}}{l}_i),1-(1-\underset{i=1}{\overset{n}{\&Pi;}}{m}_i),1-(1-\underset{i=1}{\overset{n}{\&Pi;}}{u}_i\left)\right)---\left(2\right).$

8. inefficacy thunderstorm electricity protective device according to claim 5 causes the method for personal injury loss appraisal, it is characterized in that described step 5) in, the structure function of setting event tree is Φ (X ₁, X ₂..., X _n), wherein X _ievent tree elementary event, X _ipossibility distrabtion Triangular Fuzzy Number form provide, be designated as the possibility distrabtion of top event is: median is designated as T _z.

Wherein: $T_z=\left\{\begin{array}{cc}m+\sqrt{u^2-ul},& u>1\\ m-\sqrt{l^2-ul},& u<1\end{array}\right.,$ The possibility distrabtion of elementary event is: its median is designated as T _zi.Elementary event X _ifuzzy importance S _i=T _z-T _ziif, S _i> S _j, then pay the utmost attention to and improve elementary event X _iimprove the reliability of system.