i

SISTEM BALISTIC DE CALIBRU MIC, RAPID CONVERTIBIL PENTRU ACȚIUNI LETALE ȘI NELETALE PCCA 297 / 2014 – UEFISCDI - ATM

ETAPA II, 2015 PROIECTAREA SISTEMULUI CONPOSE

raport științific și tehnic

Activitatea II.1. Definirea elementelor pentru interoperabilitatea sistemului CONPOSE

Activitatea II.2. Determinarea caracteristicilor dinamice și de stabilitate la funcționarea cu muniție neletală

Activitatea II.3. Studiu preliminar de balistică interioară. Calculul și analiza încărcăturilor propulsive

Activitatea II.4. Definirea soluției de design pentru muniție. Modelul CAD simplificat al sistemului

Activitatea II.5. Proiectarea tehnologiei de realizare a muniției neletale

Activitatea II.6. Diseminarea rezultatelor

Activitatea II.7. Definirea principalelor mecanisme ale armei pentru conversia letal / neletal

Activitatea II.8. Predefinirea elementelor pentru testarea sistemului

CONPOSE

2015

director de proiect: conf. univ. dr. ing., lt. col. marius valeriu cîrmaci -matei

departamentul de inginerie a sistemelor de armament și mecatronică academia tehnică militară, bucureşti, decembrie, 2015

Form DOT F 1700.7 (8-72)

Raport Științific și Tehnic - pagină de identificare

Raport nr. 2/2015 Aviz de consultare publică nr. Nr. de catalog

Titlul

PROIECTAREA SISTEMUL UI CONPOSE

Perioada

01 Ianuarie 2015 – 31 Decembrie 2015

Autori

Academia Tehnică Militară

Agenția de Cercetare pentru Tehnică și Tehnologii Militare

Societatea Uzina Mecanică SADU S.A.

Codul organizaţiei autorilor

ATM

ACTTM

UM SADU SA

Tipul raportului

Parțial Etapa II / 2015

Denumirea proiectului din care face parte raportul Finanțator

SISTEM BALISTIC DE CALIBRU MIC,

RAPID CONVERTIBIL PENTRU ACȚIUNI LETALE ȘI NELETALE

UEFISCDI – PCCA 2013

Contract nr. 297 / 2014

www.mta.ro; www.acttm.ro; www.umsadu.ro

Activitatea II.1. Definirea elementelor pentru interoperabilitatea sistemului CONPOSE

Activitatea II.2. Determinarea caracteristicilor dinamice și de stabilitate la funcționarea cu muniție neletală

Activitatea II.3. Studiu preliminar de balistică interioară. Calculul și analiza încărcăturilor propulsive

Activitatea II.4. Definirea soluției de design pentru muniție. Modelul CAD simplificat al sistemului

Activitatea II.5. Proiectarea tehnologiei de realizare a muniției neletale

Activitatea II.6. Diseminarea rezultatelor

Activitatea II.7. Definirea principalelor mecanisme ale armei pentru conversia letal / neletal

Activitatea II.8. Predefinirea elementelor pentru testarea sistemului

Cuvinte cheie Nivel de accesibilitate

Fără restricţii

Clasificarea de securitate a raportului Clasificarea de securitate a paginii Nr. de pagini

Neclasificat Neclasificat 20

1

CUPRINS

PCCA 297 / 2014 – UEFISCDI - ATM __________________________________________________________________ i

rezumatul etapei _____________________________________________________________ 2

obiectivele raportului __________________________________________________________ 3

Analiza mecanismelor de rănire la impact cu proiectile cinetice / kinetic projectile impacted body -

wound mechanism analysis _____________________________________________________________ 3

Teste de laborator cu muniție neletală existentă, trasă în gelatină balistică/ laboratory tests with

nonlethal ammunition in balistic gelatin __________________________________________________ 4

Calibrarea gelatinei / gelatin calibration __________________________________________________ 5

Fabricarea și testarea unor muniții de laborator / laboratory ammunition tests _________________ 6

Studierea unei soluții pentru tragere neletală cu arme de mână / adaptive over caliber nonlethal

configuration _________________________________________________________________________ 8

Rutina de calcul pentru analiza ciclului dinamic al armei ____________________________________ 13

Elemente componente ale mecanismului motor în arma proiecta tă: ___________________________________ 13

Extras din rutina de calcul: ________________________________________________________________________ 14

Modele 3d pentru mecanismul armei de proiectat și pentru muniția CONPOSE ________________ 16

Muniția CONPOSE proiectată și realizată în cadrul etapei ___________________________________ 18

2

REZUMATUL ETAPEI În Etapa II au fost preluate și dezvoltate rezultatele intermediare ale Etapei I. Astfel, pentru studierea comparativă a

efectului terminal obținut cu viitoarea muniție CONPOSE au fost efectuate teste cu diferite tipuri de muniție

neletală de pe piață. Testele au constat în trageri de laborator, folosind gelatina balistică drept stimulant/surogat

uman. Ulterior, o serie de teste au fost reproduse prin simulare numerică pentru a găsi legea de material adecvată

comportamentului gelatinei. Aceasta va fi utilă în simularea muniției proiectate. Odată calibrate proprietățile

mecanice ale gelatinei balistice, putem dezvolta teste virtuale consistente pentru caracterizarea muniți ei.

Pentru determinarea impulsului transmis la țintă s -a conceput un sistem de măsurare a forței de impact în raport

cu timpul. Valoarea impulsului transmis are rol determinant în analiza efectului neletal. S-au folosit mai multe

configurații de proiectile cinetice neletale, pentru analiza mecanismului specific de transmitere a impulsului. În

acest sens am produs mai multe muniții neletale de laborator: baloane cu făină de calibru 40 mm, similare unei

muniții neletale aflate în uz în jandarmeria franceză, muniție de calibru 9 mm din teflon sinterizat și muniție de

silicon, de calibre diferite (8 mm, 9 mm, 10 mm, 12 mm). A fost necesară proiectarea și realizarea unei matrițe

pentru muniția de silicon. Pentru reducerea timpului de testare cu trageri în poligon a fost adaptat un sistem de

bare Hopkinson (Split Pressure Hopkinson Bar) pentru a folosi ca sistem de lansare cu aer comprimat. Au fost

proiectate și realizate piese și ansambluri în acest sens. De asemenea, a fost realizat un pendul balistic de laborato r

pentru măsurarea impulsului la țintă obținut cu muniție foarte ușoară.

O variantă de armă neletală studiată în cadrul etapei are drept punc t de plecare un pistol de mână. A fost analizată

o soluție ingenioasă pentru trageri neletale fără modificări ale mecanismului armei. Ideea analizată presupune

atașarea unei bile de masă crescută la gura țevii. Muniția letală face corp comun cu bila în momentul tragerii,

rămânând captivă în aceasta. Materialul bilei este deformat controlat, astfel încât la impact să realizeze valori de

energie pe suprafață sub limita de letalitate. Caracteristicile dinamice ale bilei se obțin din conservarea energiei și

impulsului.

Au fost studiate caracteristicile dinamice ale armelor de calibru mic similare pentru a aduce sistemul CO NPOSE în

zona de interoperabilitate cu sistemele letale echivalente.

Analiza ciclului dinamic al armei a presupus realizarea unui program de calcul care să integreze ecuația de mișcare a

mecanismului reculant, ținând cont de legăturile cinematice dintre el ementele conducătoare și cele conduse.

Condițiile inițiale sunt determinate prin rularea unei rutine de calcul a parametrilor de balistică interioară.

O primă versiune de design pentru muniția CONPOSE a fost produsă și pregătită pentru teste reale în gelatină

balistică. Testele de stabilitate pe traiectorie și precizie au dat rezultate promițătoare. Procesul tehnologic de

realizare a muniției a fost realizat.

Principalele mecanisme ale armei au fost modelate 3D și se lucrează la adoptarea soluției optime de conversie letal

/ neletal.

Concluzie: Datorită constatării potențialului letal la muniția de laborator utilizată în Etapa I, am considerat extrem

de important să dezvoltăm o serie de teste și echipamente de testare pentru caracterizarea conținutului energetic

al viitoarei muniții CONPOSE și pentru analiza mecanismului de rănire. O variantă de muniție a fost creată și

urmează testarea acesteia la viteze care să asigure funcționarea automată a mecanismului armei. Caracteristicile

dinamice ale armei sunt evaluate cu un program creat pentru integrarea ecuațiilor de mișcare.

OBIECTIVELE RAPORTULUI

În această etapă au fost urmărite și atinse următoarele obiective ale proiectului:

Analiza mecanismelor de rănire la impact cu proiectile cinetice

Teste de laborator cu muniție neletală existentă, trasă în gelatină balistică Calibrarea proprietăților de material pentru gelatina balistică fabricată în laborator, în vederea

reproductibilității testelor virtuale

Caracterizarea cerinţelor privind efectul neletal al sistemu lui, prin studii experimentale şi simulare numerică a unor configuraţii inovatoare de muniţii

Fabricarea unor muniții de laborator cu caracteristici diferite, pentru analiză comparativă Adaptarea sistemului Hopkinson pentru funcționare ca armă cu aer comprimat

Proiectarea și fabricarea unui set de dispozitive de lansare pentru muniție de silicon de diferite calibre Proiectarea și realizarea unei matrițe pentru muniție de silicon Proiectarea și realizarea unui pendul balistic pentru analiza impulsului transferat ți ntei Studierea unei soluții pentru tragere neletală cu arme de mână

Analiza caracteristicilor unor arme de comparație Rutină de calcul pentru analiza ciclului dinamic al armei Proiectarea tehnologiei de realizare pentru muniția CONPOSE

Fabricarea unui prim lot de muniție pentru teste Modele 3D pentru mecanismul armei

ANALIZA MECANISMELOR DE RĂNIRE LA IMPACT CU PROIECTILE CINETICE / KINETIC PROJECTILE

IMPACTED BODY - WOUND MECHANISM ANALYSIS

The goals of our work are to analyse the impact between nonlethal ammunition and human body. Despite the fact

that a weapon cannot really be called nonlethal (any weapon has a probability to kill), we have chosen to use this

term because it is the most common in any publication. And the lethality level must be known, with respect to

caliber, velocity and the material in which the ammo is manufactured. Also, the distance to target p lays a major

role.

Usual damages when using nonlethal or less -lethal ammunition are rib fracture, pulmonary contusion and heart

damage. Besides the Abbreviated Injury Severity Scale (AIS), there are more experimental methods for trauma

analysis: Bowen curves and modified Bowen curves, Axelsson criterion (chest wall velocity predictor) or Back Face

Signature (BFS). Some of them are more dedicated to describe the effects of shock waves transmitted through the

body or even the effect of a lethal ammo against a body protected with a ballistic vest. Because of a lack in

nonlethal systems standardization from the market, the effects against human tissue may differ on a large scale.

That is why additional laboratory devices and procedures may be useful in addition to the widely accepted tests .

• Rib fracture

• Pulmonary contusion

• Heart damage

AIS = Abbreviated Injury Severity (Scale) key informations:

• This type of scale is different for each part of our body and connects the 6 levels of it to the type of injury

that is endured

• Possible values are between 0 (no any danger and 6 (survival chances less than 1%)

Despite the fact that a weapon cannot really be called "non-lethal" (any weapon has a probability to kill), we have

chosen to use this term because it is the most common in any publication. Even with the previous definition, we

can still wonder what can be inferred by "incapacitate" or "permanent injuries" for instance. To answer more

precisely to that question, some specialists have created the AIS (for Abbreviated Injuries Scale). This type of scale

is different for each part of our body and connects the 6 levels of it to the type of injury that is endured. Thanks to

these scales, it is now possible to determine if a weapon is lethal (AIS >=3) or non-lethal (AIS<=2). In the table, we

can see the 6 different levels of the AIS for the thorax.

AIS Injury severity Skeletal injury Soft tissue injury

1 Minor 1 rib fracture Contusion of bronchus

2 Moderate 2-3 rib fractures

Sternum fracture

Partial thickness bronchus tear

3 Serious 4 or more rib fracture on one side

2-3 rib fractures with

hemo/pneumothorax

Lung contusion

Minor heart contusion 4 Severe Flail chest

4 or more rib fractures on each side

4 or more rib fractures with

hemo/pneumothorax

Bilateral lung laceration

Minor aortic laceration

Major heart contusion

5 Critical Bilateral flail chest Major aortic laceration

Lung laceration with tension

Pneumothorax

6 Maximum Aortic laceration with haemorrhage not

confined to mediastinum

There are several experimental methods for trauma analysis:

• Bowen curves (for explosions) • Modified Bowen curves

• Axelsson criterion (Chest Wall Velocity Predictor, CWVP) • Balistic gelatin - the method we well use on large scale • Standards for body armour testing:

• NIJ Standard 0101.06 in USA, 2008 • HOSDB Body Armour Standards for UK Police, 2007, Part 2: Ballistic Resistance • AEP 94, NATO • Back Face Signature (Behind Armour Blunt Trauma - 44 mm maximum accepted)

TESTE DE LABORATOR CU MUNIȚIE NELETALĂ EXISTENTĂ, TRASĂ ÎN GELATINĂ BALISTICĂ/

LABORATORY TESTS WITH NONLETHAL AMMUNITION IN BALISTIC GELATIN

The test was performed with fresh gelatin and small bullets

A ballistic radar measured the bullet velocity and high speed camera helped to measure the stoping time.

Bullet weight = 0.5 g

Bullet density = 14.92 g/cm3

Max depth = 61 mm

Time to stop = 1.5 ms

Width cavity = 10 mm

CALIBRAREA GELATINEI / GELATIN CALIBRATION

Software features for simulation:

• Nonuniform distribution of grid in gelatin block – fine mesh in front of ball

• Viscoelastic behavior approximate through a simple elasto-plastic behavior

• Erosion criteria – the value for erosion strain is 0.9

The simulated evolution of bullet velocity and penetration depth shows similar to the values gathered with

highspeed camera:

FABRICAREA ȘI TESTAREA UNOR MUNIȚII DE LABORATOR / LABORATORY AMMUNITION TESTS

The work undertook during the shooting sessions was to evaluate and improve the performances of a 40 mm

projectile made by flour. Flour is convenient to create nonlethal projectiles because these rounds can deform

rapidly and significantly, which leads to an impact surface bigger than the initial one, thus reducing th e risk of

irreversible injuries. Mention that a better optimization of the impact force distribution requires special

mechanical properties of the rubber, which may not be found in usual choices from the market. Also, the flour

granulation and composition properties (as water content) are very important. A similar ammunition already exists

and is used by the French police. The only public data are that it is a single projectile with a diameter of 56 mm

made from a latex envelope which contains 180 g of flour. During the shooting session a high speed camera was

used to have a global idea of the projectile behavior and was aimed at the end of the trajectory. The RADAR was

also used to measure the velocity as a function of time or distance. One of the shooting sessions was held outside

but seeing that it was not windy and that the projectiles are relatively heavy, it should not have induced big errors

on the results. In this case, the cartridges were assembled out of five different parts as in figure below. A metallic

high pressure chamber where the primer is placed, a metallic base which is the low pressure chamber, a carton

plug, a carton covered with plastic and a balloon filled with flour being the projectil e. The base has a diameter of 40

mm and a height of 46 mm. The ignition of the powder takes place in the high pressure chamber. As propellant,

0.55 g of SB 620 powder were used in each cartridge. The carton plug delimits the space of the low pressure

chamber that is why it does not have to be so resistant. It’s role is to protect the balloon from the hot combustion

gases. The carton covered with plastic is placed around the projectile to protect it from the frictions with the tube

and has to be rolled in the good direction in order to follow the rifling of the barrel. The balloon weighs 2.5 g and is

filled with 75 g of flour what makes a projectile of around 77.5 g.

The weapon used was a M79 which is a single-shot grenade launcher used by the US Army.

Two different targets were used during this session: a wooden structure and a foam torso mannequin . The wooden

structure was used as first target only to see how the projectile reacts and was situated at 16 meters from the

shooter. The maximum surface of the projectile at the wooden structure is than equal to 67 cm2 but this will never

occur when hitting a soft target like the human body. It only may be used to verify that the energy density will

never be lower than the threshold considering the minimum value for an effective impact of 3,62J/cm2, as in table

bellow:

Area Criterion Energy density Threshold value

Skin 50% probability to have penetration on the anterior rib 23.99 J/cm2

Skin Minimal value to have a sufficient impact 3.62 J/cm2

Eyes 50% probability to have corneal abrasion 0.15e-3 J/cm2

Eyes 50% probability to have a globe rupture 2.38e-3 J/cm2

The most important parameter that was measured is the velocity of the projectile that permits to calculate the

energy as well as the maximum energy density. In the next table, the distance at which the velocity was measured,

the velocity, the energy, the maximum and the minimum energy density are recapitulated.

Results for outdoor shootings

The velocity taken at 5 meters gives a precise value and

not an extrapolated one. For shot 1, the velocity is given at

15 meters because it was when the wooden structure was

the target which was situated 16 meters away from the

shooter.

The measured results show that five of the eleven shots

have an energy higher than the theoretical limit of 78 J.

Due to the big surface of impact of these projectiles, their

energy density is lower than the one theoretically needed

to perforate the skin. This is not surprising at all because

the risk of penetration of a projectile of 40 mm is very low

nay non-existent. However, the minimal energy density, calculated based on the maximal surface of impact, is

always lower than the limit. It does not mean that this projectile will not be effec tive when impacting an human

because the projectile should normally not deform so much. Tests on biofidelic targets should be held to confirm

this. If necessary, the velocity or the mass of the projectile should be increased. Making an heavier projectile wou ld

be the easiest solution if the same weapon is used for further shots.

Given these first results, more tests have to be held in order to assess whether or not this projectile can be

considered as non-lethal. Optimally, the effec tive range of this projectile should also be determined. Because of the

problems that occurred, some modifications have first to be made.

The case was too short so the carton covered with plastic has to be glued on its length and it has sometimes lead to

the impact of this one on the target with the projectile. The solution is to make a longer case to not have to glue

the carton. This case could also be made in plastic because the pressure in this chamber is not so high and a hard

plastic could be resistant enough. This would let the price of the cartridge decrease a bit. Other optimizations cover

the burning velocity of the powder namely increasing it, and the projectile stability. As can be seen, a large number

of new projectiles must be fired. For a better stability we have chosen to make spherical projectiles, particularly

with a fabric tail.

Given all these claims, an indoor set up was required. In

this way a large amount of primers and ammunition

parts were saved and the time efficiency increased.

During this session, a pneumatic launcher of 60 mm

diameter was used. In order to fire the flour projectiles,

which have a diameter of 40 mm, a sabot was placed

around the projecti le. This sabot is made of two parts

that can be separated: a full hard teflon piece and an

aluminium element.

The sabot and the pneumatic launcher

This sabot was supposed to help the pressure to rise inside the barrel in order for the pro jectile to have a sufficient

initial velocity. But, at the same time, due to its big size and, by consequent, big impact surface, the frictions it

undergoes during its travel in the barrel are not negligible. These frictions were reduced, lubricating the whole

surface of the teflon piece. This launcher is used together with an air compressor. It allows to regulate the initial

pressure in the barrel, which is directly linked with the velocity. The entire set-up has a sabot stopper and, 50 cm

on the right side, a force transducer with a flat surface of impact. This also allows to see the behavior of the

projectile when impacting a rigid surface.

Face and side view of the force transducer

STUDIEREA UNEI SOLUȚII PENTRU TRAGERE NELETALĂ CU ARME DE MÂNĂ / ADAPTIVE OVER

CALIBER NONLETHAL CONFIGURATION

In order to simplify the process of adopting a new weapon, this work bases its research on a patent regarding a

magazine-loaded over-caliber non lethal energy projectile initiated by projectile of the live ammunition with

pivoting magazine assembly, patent number WO2000014473 A1 dating from 16th of March 2000. So, in order to

overcome the deadly force transported by a lethal pistol, the adaptive over-caliber non lethal system was proposed

to the Ferguson Police. It is designed to be mounted on the standard police firearmGlock® 19:

The over-caliber non lethal system

To be able to verify this system’s proprieties and

performance, the current work proposes an over-

caliber non lethal system adapted for the standard

issue Romanian security forces sidearm: the Cugir

LP5 pistol, chambered for the 9x19 mm

Parabellum ammunition. Next figure illustrates the

Cugir pistol, together with the mounted over-

caliber non lethal system.

The over-caliber non lethal system adapted and

mounted on the Cugir LP5 pistol

The adapted system consists of two elements: the mount, which is fixed on top of the slide of the pi stol and the

over-caliber ball which has a hole drilled on one side that is aligned with the barrel and another 4 holes that allow it

to be supported by the 4 arms of the mount. In order to check if the mount can withstand the weight of the ball,

which is around 100 grams, a static finite element analysis simulation was taken using SolidWorks® Simulation

software. The results are shown in next figure.

The maximum displacement obtained on the mount by the

static weight of the ball

The solver concludes the fact that the maximum displacement of

one arm is around 0.4 mm. The material does not exceed its

elastic limit. In this configuration, the over-caliber system should

not comport deformations that could alter the firing process and

the safety of the shooting.

Upon firing, the 9 mm bullet will exit the muzzle and will enter

the hole drilled in the ball, which is concentric with the barrel.

Due to the impulse transfer, the bullet will travel together with

the over-caliber ball towards the target, with a lower velocity

and, from a certain point, with a reduced kinetic energy. Due to the intermediate ballistics, a consideration

regarding the place where the ball will be placed must be made. After running an assessment for the interior

ballistics and considering the drop of pressure after the bullet lea ves the barrel of the pistol, and the

recommendation that any muzzle velocity recording device should be placed at a least 4, 5 calibers distance from

the muzzle, a distance of 35 mm is suitable for mounting the over-caliber ball.

Up to this point, the non lethal proposed system looks suitable for equipping the LP5 pistol. The testing of the

exterior and terminal characteristics are the next steps to be achieved in order to assess the performance of the

over-caliber system. A numerical simulation for the behavior of the bullet-ball assembly can foresee the behavior of

the bullet-ball assembly on the trajectory. In the beginning, there are two important things that have to be

assessed. What may be the trajectory, the velocity during the path and what is the kinetic energy that may be

transmitted during the path towards target.

The exterior ballistics of the new formed projectile is important in order to verify the distance it can be

carried towards target. Having known the mass of the ball, which is 100 grams in this case, the mass of the 9 mm

bullet (8 grams) and the initial velocity of the bullet (380 m/s), the initial velocity of their assembly can be

calculated by considering the conservation of the momentum for th e ideal case of a plastic impact.

𝑚𝑏𝑢𝑙𝑙𝑒𝑡 𝑉0.𝑏𝑢𝑙𝑙𝑒𝑡 = 𝑚𝑏𝑢𝑙𝑙𝑒𝑡 + 𝑚𝑏𝑎𝑙𝑙 𝑉0.𝑏𝑎𝑙𝑙

where:

𝑚𝑏𝑢𝑙𝑙𝑒𝑡 represents the mass of the bullet;

𝑉0.𝑏𝑢𝑙𝑙𝑒𝑡 represents the initial velocity of the bullet;

𝑚𝑏𝑎𝑙𝑙 represents the mass of the over-caliber ball;

𝑉0.𝑏𝑎𝑙𝑙 represents the initial velocity after impact of the bullet-ball assembly.

The initial velocity of the bullet-ball assembly is calculated to be 28 m/s. For a ball, using the Siacci method for

calculating the trajectory of a projectile, the ballistic coefficient will be 1.5. The obtained trajectory for different

shooting angles have been plotted with Matlab® and are illustrated further.

The trajectory for the bullet-ball assembly, shooting angle of 1o

The trajectory for the bullet-ball assembly, shooting angle of 5o

As it was expected, the total length of the trajectory is highly diminished. Numerical simulations calculated that at a

shooting angle of 1o, the maximum obtained trajectory is 25 m. At a shooting angle of 2 o, the maximum

longitudinal distance is around 46 m and at a shooting angle of 5o, which still allows the direct aiming in facile

conditions, the maximum trajectory length will be around 100 m. This is due to the fact that the mass of the

projectile is larger, the ballistic coefficient is larger and the initial velocity is smaller.

If we consider what would the amount of energy be when the bullet-ball assembly forms, so when its initial velocity

will be 28 m/s, then one can calculate the initial kinetic energy to be 42.3 J and the ini tial energy density will be

0.043 J/mm2 if we consider the contact surface to be 1/2 of the sphere exterior diameter. In both situations, the

data is below the lethality threshold stated by NATO standards. Due to the normal involution of the assembly’s

velocity, these values will be the highest data that may be obtained on the path throughout the trajectory, so that

the non lethal effect will be accomplished on each distance step.

A finite element analysis was performed in order to foresee the behavior of the bullet and the ball during and after

the impact. The software used in order to achieve this is LS-Dyna. In order to simplify the simulation, basic

materials have been chosen for the bodies involved. The bullet is considered to be consisted only of lead, so its

bimetallic jacket is neglected. The ball is consisted of 2024 T351 strengthen aluminum, on the inside, and of

Mooney-Rivlin rubber on the outside. These materials have been chosen from the solver’s database. Since we are

dealing with a axis symmetrical 3D real situation, for the ease of computation the problem is reduced to a axis

symmetrical 2D situation. The chosen mesh is fine on the assumed impact area and coarser towards the exterior of

the ball. Also, an impact between the over-caliber assembly and a rigid wall is tested.

Initial configuration: the bullet (green), the ball (inner part in blue, outer part

in red) and the rigid wall (yellow)

The dynamical contact between the bullet and the ball produces a local energy

transfer, which causes different particle velocities inside the materials. After a

period of time of 5e-7 seconds, the assembly commenc es moving as a single

body, with an initial velocity of about 30 m/s . After a period of 2e-4 seconds,

the assembly impacts the rigid wall.

Simulated contact between the bullet and the ball and between the assembly and the rigid target:

Evolution of velocity after the impact between the bullet and the ball. A – bullet velocity; B – inner ball part

velocity; C – outer ball part velocity:

After the impact between the bullet and the aluminum part of the ball , there is an energy transfer and the three

components begin marching together, but with different velocities. After the impact with the rigid surface, due to

the elasticity of the rubber, the ball bounces back, thing that is reflected in the negative side of the velocity plot.

The finite element simulation was performed with an initial bullet velocity of 380 m/s. The materials were chosen

so that a perforation of the ball is not achieved. For tunately, the 9 mm bullet is round nosed, so it does not possess

material perforation characteristics as good as a rifle bullet, i .e. the SS109 from the 5 .56 mm NATO ammunition.

The 2024 T351 aluminum offers good mechanical resistance and due to its reduced density, when compared to

steel, contributes to a lighter over-caliber ball mass. The Mooney-Rivlin rubber is a hyperelastic material, which

performs well during the impact with a rigid body. The energy transfer mechanism during the impact between the

ball assembly and the rigid target is highly dependent on the exterior casing of the ball. If the chosen material is too

elastic, the terminal effects can be diminished and if the rubber is too ri gid, case that could also be possible from

the ageing of the material, the impact mechanism could produce serious injuries to the target.

According to the numerical simulations, the presented configuration may be suitable for the 9 mm Cugir pistol. It

performs safely and it manages to transport the ball assembly towards the target on an acceptable trajectory (up to

100 m for direct aiming). What is still to be acknowledged is the precision of this non lethal system, the distance for

which the accuracy is satisfying and what are the real effects upon the human target.

As a conclusion, the non lethal over-caliber system for the Cugir pistol may be an option for extending the shooting

capabilities of Romania’s Army sidearm weapon. Also, this system may be extended to different kinds of weapons,

i .e. the 40 mm grenade launcher. Besides the performance and terminal requirements, there are still issues that

need to be settled.

The ergonomics of the weapons is one of the issues that need a close assessment. So, the question that

arises is: is the non lethal over-caliber system suitable for firing within keeping the ergonomics of the pistol?

Economically speaking, there is a major total price difference between a newly designed non lethal weapon and the

presented adapted platform. But is this platform going to meet the needs of the shooter, with respect to the speed

of response to different threats and to the right response depending on the situation? There are, though, enough

things to be accounted for in order to proceed with the development of this system. So, the final step will be the

shooting range trials, where persons interested in it should make sure that all the important fields regarding the

over-caliber system are verified.

RUTINA DE CALCUL PENTRU ANALIZA CICLULUI DINAMIC AL ARMEI

Pentru analiza ciclului dinamic au fost efectuate următoarele:

- Proiectarea CAD a elementelor armei de comparație

- Determinarea maselor și momentelor de inerție

- Determinarea diagramei de ciclu

- Determinarea forțelor și momentelor

- Scrierea ecuațiilor de mișcare pentru mecanismul reculant

Drept armă de comparație este aleasă o pușcă de asalt cal. 5,56 mm.

Diagrama de ciclu a armei de comparație:

ELEMENTE COMPONENTE ALE MECANISMULUI MOTOR ÎN ARMA PROIECTATĂ:

EXTRAS DIN RUTINA DE CALCUL:

Pentru arcul recuperator a fost necesară evaluarea pierderilor energetice din materialul arcului (în spire, la

funcționare). În absența acestei subrutine, forța elastică a arcului este constantă și rezultatele teoretice nu

corespund măsurătorilor practice. Viteza mecanismului reculant are o evoluție cvasiliniară și amortizarea este

insuficientă (curba albastră de mai jos). Odată cu calcului pierderilor, viteza de recul calculată capătă o evoluție

firească și corespunde valorilor măsurate experimental (curba roșie).

Diferența dintre viteza mecanismului reculant cu și fără evaluarea pierderilor energetice din materialul arcului

recuperator:

Viteza mecanismului reculant la recul și revenire:

MODELE 3D PENTRU MECANISMUL ARMEI DE PROIECTAT ȘI PENTRU MUNIȚIA CONPOSE

DENUMIREA și IMAGINEA PIESEI DENUMIREA și IMAGINEA PIESEI

TRĂGACI

AGĂȚĂTOR

COCOȘ

ÎNCETINITORUL CO COȘULUI

ANSAMBLUL FORMAT DIN TRĂGACI, AGĂȚĂTOR,

ÎNCETINITORUL CO COȘULUI ȘI ZĂVOR

AUTODECLANȘATOR

PORTÎNCHIZĂTOR

ÎNCHIZĂTORUL, ÎMPREUNĂ CU

EXTRACTORUL ȘI CUIUL PERCUTOR

CUTI A MECANISMELOR

NOUL ÎNCHIZĂTOR, PRODUS DIN

ÎNCHIZĂTORUL EXISTENT, CĂRUIA I-

AU FOST ELIMINATE NUCILE DE

ÎNZĂVORÂRE

NOUA CUTIE A ME CANISMELOR, CARE

ARE MONTATE PE CAPACUL

POSTERIOR DOUĂ ARCURI CE AU

ROLUL DE A SPORI ENERGIA DE

REVENIRE A MASEI RECULANTE

Dispunerea pieselor mecanismului motor:

MUNIȚIA CONPOSE PROIECTATĂ ȘI REALIZATĂ ÎN CADRUL ETAPEI

9x19 mm și 7,62 mm

5,56 mm