SU954849A1

SU954849A1 - Stand for testing material specimen for extension

Info

Publication number: SU954849A1
Application number: SU813255127A
Authority: SU
Inventors: Валентин Никитич Потураев; Виталий Илларионович Дырда; Анатолий Викторович Коваль; Александр Александрович Ратушный
Original assignee: Институт Геотехнической Механики Ан Усср
Priority date: 1981-03-04
Filing date: 1981-03-04
Publication date: 1982-08-30

Description

Изобретение относится к испытательной технике и может быть· использовано при определении упругих характеристик вязкоупругих материалов при растяжении.The invention relates to testing equipment and can be used to determine the elastic characteristics of viscoelastic materials under tension.

Известен стенд для испытания образцов материала на растяжение,содержащий станину и установленные на ней неподвижный захват для крепления »о образцов, нагружающее устройство в виде поршня с пружиной .сжатия, стопорный механизм и регулируемый упор, подвижный захват и сплошной шток, один конец которого связан с 15 нагружающим устройством, а второй - . с подвижным захватом [ij .A well-known stand for testing samples of material in tension, containing a frame and mounted on it a fixed grip for mounting "about samples, a loading device in the form of a piston with a spring. Compression, locking mechanism and adjustable stop, movable grip and a solid rod, one end of which is connected with 15 loading device, and the second -. with movable gripper [ij.

Недостатком этого стенда является низкая точность определения на нем значения мгновенного модуля упругое- ²⁰ти, так как скорость нагружения об- ι разца пружиной сравнительно невелика, а также из-за того, что по ме ре релаксации напряжений и деформации ползучести, вызывающих деформацию пружины, изменяется усилие на образец и его размеры.The disadvantage of this stand is the low accuracy of determining the value of the instantaneous modulus of elasticity ^{on it} , since the loading speed of the specimen with a spring is relatively small, and also due to the relaxation of stresses and creep deformation causing spring deformation, the force on the sample and its dimensions change.

Цель изобретения - повышение точности при определении мгновенного модуля упругости вязкоупругих материалов.The purpose of the invention is improving accuracy in determining the instantaneous modulus of elasticity of viscoelastic materials.

Для достижения указанной цели стенд для испытания образцов материалов на растяжение, содержащий станину и установленные на ней неподвижный захват для крепления образцов, нагружающее устройство, стопорный механизм и регулируемый упор, подвижный захват и шток, один конец которого связан с нагружающим устройством, а второй - с подвижным захватом, снабжен размещенным на станине электромагнитным- фиксатором, шток выполнен из двух частей, связанных между собой с помощью разделительной муфты, выполненной в виде_ν рычагов, установленных на одной части штока^с возможностью взаимодействия с регулируемым упором, и подпружиненных штифтов, размещенных на второй части штока и взаимодействующих с рычагами, а стопорный механизм и электромагнитный фиксатор установлены с возможностью взаимодействия с частью штока, связанной с подвижным захватом.To achieve this goal, a test bench for tensile testing of samples of materials, containing a bed and a fixed grip mounted on it for fastening the samples, a loading device, a locking mechanism and an adjustable stop, a moving grip and a rod, one end of which is connected to the loading device, and the second to movable gripper, equipped with an electromagnetic lock placed on the bed, the rod is made of two parts interconnected by means of a separation sleeve made in the form of _ν levers mounted on one th part of the rod ^ with the possibility of interaction with an adjustable stop, and spring-loaded pins placed on the second part of the rod and interacting with levers, and the locking mechanism and electromagnetic lock are installed with the possibility of interaction with the part of the rod associated with the movable grip.

Кроме того, нагружающее устройство выполнено в виде электромагнита, внешний якорь которого жестко'связан со штоком.In addition, the loading device is made in the form of an electromagnet, the external anchor of which is rigidly connected to the rod.

На фиг.1 изображен стенд, вид сбоку, на фиг.2 - разделительная муфта; на фиг.З ~ стопорное устройство и электромагнитный фиксатор.Figure 1 shows a stand, side view, figure 2 - dividing clutch; in Fig.Z ~ locking device and electromagnetic lock.

Стенд содержит станину 1, установленный на ней неподвижный захват 2, размещенный в едином корпусе 3 стопорный механизм, выполненный в виде расположенных в отверстиях корпуса 3 шариков 4 с пружинами 5. коромысел 6, одни концы которых установлены с возможностью взаимодействия с шариками 4, и установленной на корпусе 3 с возможностью взаимодействия с вторыми концами коромысел 6 гайки 7, и электромагнитный фиксатор 8 с подвижным элементом 9. Стенд содержит также регулируемый упор 10, размещенный на станине 1, подвижный захват 1 ] , шток, состоящий из двух частей 12 и 13, связанных разделительной муфтой, выполненной в виде рычагов 14 и 15, установленных на части 12 штока, связанной с подвижным захватом 11 и взаимодействующей с шариками 5 стопорного механизма, с возможностью взаимодействия одними своими концами с регулируемым упором 10, и штифтов 16 с пружиной 1/взаимодействующих с вторыми концами рычагов 14 и 15 и установленных .на части 13 штока.The stand contains a frame 1, a fixed grip 2 installed on it, a locking mechanism located in a single housing 3, made in the form of balls 4 with springs 5. located in the holes of the housing 3, rocker arm 6, one ends of which are installed with the possibility of interaction with balls 4, and installed on the housing 3 with the possibility of interacting with the second ends of the rocker arm 6 of the nut 7, and an electromagnetic lock 8 with a movable element 9. The stand also contains an adjustable stop 10 located on the frame 1, a movable gripper 1], a rod consisting of two parts 12 and 13 connected by a separation clutch made in the form of levers 14 and 15 mounted on part 12 of the rod associated with the movable gripper 11 and interacting with the balls 5 of the locking mechanism, with the possibility of interaction with one of their ends with an adjustable stop 10, and pins 16 with a spring 1 / interacting with the second ends of the levers 14 and 15 and installed. on the part 13 of the rod.

Кроме того, стенд содержит ось 18 с пружиной 19, установленной в части 12 штока с возможностью взаимодействия с подвижным элементом 9 электромагнитного фиксатора 8, нагружающее устройство, выполненное в виде установленного на станине 1 электромагнита 20, внешнийякорь 21 которого жестко связан с концом части 13 штока, и систему 22 измерения усилий и деформаций.In addition, the stand contains an axis 18 with a spring 19 installed in the rod part 12 with the possibility of interaction with the movable element 9 of the electromagnetic lock 8, a loading device made in the form of an electromagnet 20 mounted on the frame 1, the external armature 21 of which is rigidly connected to the end of the rod part 13 , and a system 22 for measuring stress and strain.

Стенд работает следующим образом.The stand works as follows.

Закрепляют образец 23 в неподвижном захвате 2 и подвижном захвате 5 11 и устанавливают регулируемый упор 10 таким образом, чтобы расстояние между ним и концами рычагов 14 и 15 было равно заданной деформации образца 23· Включают электромагнит 20, 10 который притягивает якорь 21 со штоком. Образец 23 не растягивается, так как шток застопорен фиксатором 8.The sample 23 is fixed in a fixed grip 2 and a movable grip 5 11 and an adjustable stop 10 is installed so that the distance between it and the ends of the levers 14 and 15 is equal to the predetermined deformation of the sample 23 · Turn on the electromagnet 20, 10 which attracts the armature 21 with the rod. Sample 23 is not stretched, since the rod is locked by a retainer 8.

После того, как значение электромагнитной силы в электромагните 20 15 достигнет своего максимального значения, включают фиксатор 8, подвижный элемент 9 которого воздействует на ось 18 и освобождает шток, которой, перемещаясь, растягивает обра20 зец 23. При перемещении штока концы рычагов 14 и 15 упираются в регу-’· лируемый упор 10, поворачиваются, давят на штифты 16 и разъединяют части 12 и 13 штока друг от друга. 25 Часть 13 перемещается далее до окончания хода внешнего якоря 21 электромагнита 20, а часть 12 стремится переместиться в другую сторону под действием сил упругости образца 23· ₃₀ Шарики 4 заклиниваются между 'After the value of the electromagnetic force in the electromagnet 20 15 reaches its maximum value, turn on the lock 8, the movable element 9 of which acts on the axis 18 and releases the rod, which, moving, stretches the sample 23. When moving the rod, the ends of the levers 14 and 15 abut in the adjustable stop 10, they turn, press on the pins 16 and disconnect the parts 12 and 13 of the rod from each other. 25 Part 13 moves further until the end of the course of the outer armature 21 of the electromagnet 20, and part 12 tends to move to the other side under the action of the elastic forces of the sample 23 · ₃₀ Balls 4 are wedged between

- частью 1.2 штока и корпусом 3 и фиксируют часть 12 штока и образец 23 в растянутом до заданных деформаций . состоянии, измеряют усилие, действу55 ющее на образец 23, и его деформацию в момент заклинивания штока и по этим значениям, полученным при высоких скоростях нагружения, рассчиты• вают значение мгновенного модуля упругости. Измеряя усилие и деформа-·, цию образца в заданный момент времени после нагружения, фиксируют изменение значения модуля упругости в зависимости от времени нагружения.- part 1.2 of the rod and the housing 3 and fix part 12 of the rod and the sample 23 is stretched to the specified deformations. state, measure the force acting on the sample 23, and its deformation at the time of stem jamming, and using these values obtained at high loading speeds, calculate the value of the instantaneous modulus of elasticity. Measuring the force and deformation of the sample at a given point in time after loading, a change in the value of the elastic modulus is recorded depending on the loading time.

_4S После окончания измерения и испытания отключают электромагнит 20 и соединяют обе части 12 и 13 штока. Затем поворачивают гайку 7 до ее взаимодействия с концами коромысел 6,которые выталкивают шарики 4 и освобож⁵⁰ дают шток. _4S After completing the measurement and testing, disconnect the electromagnet 20 and connect both parts of the rod 12 and 13. Then turn the nut 7 until it interacts with the ends of the rocker arm 6, which push the balls 4 and releasing ⁵⁰ give the stock.

Предлагаемый стенд позволяет определить значения мгновенного модуля упругости вязкоупругих материалов за счет использования электромагни⁵⁵ та в качестве нагружающего устройства и автоматизированной системы разъединения штока и фиксации образца, а также значения высоких скоростей исходного деформирования образца материала и исключить динамических воздействий на образец.The proposed stand allows you to determine the instantaneous elastic modulus of viscoelastic materials through the use of an electromagnet ⁵⁵ t as a loading device and an automated system for disengaging the rod and fixing the sample, as well as high initial strain rates of the material sample and to exclude dynamic effects on the sample.

Claims

The invention relates to a testing technique and can be used in determining the elastic characteristics of the elastic elastic material under tension. A stand for testing material samples for stretching, containing a frame and fixed supports for mounting samples, a loading device in the form of a piston with a spring, a compression device, a locking mechanism and an adjustable stop, a movable pickup and a solid rod, one end of which is connected with a loading device, and the second with a movable gripper RZ. The disadvantage of this test bench is the low accuracy of determining the instantaneous modulus of elasticity at the value, since the spring loading rate of the sample is relatively small, and also due to the fact that, due to stress relaxation and creep deformation, causing the spring to deform, the force changes on the sample and its dimensions. The purpose of the invention is to improve the accuracy in determining the instantaneous modulus of elasticity in viscous materials. To achieve this goal, a stand for testing samples of materials for stretching, containing a frame and fixed clamping devices mounted on it, a loading device, a locking mechanism and an adjustable stop, a movable clamp and a rod, one end of which is connected to the loading device and the second - with a movable gripper, provided with an electromagnetic lock placed on the frame, the rod is made of two parts interconnected by means of a separating coupling, made in the form of 39 levers mounted on one part of the stem with the possibility of interaction with an adjustable stop, and spring-loaded pins located on the second part of the stem and interacting with the levers, and the stopper mechanism and electromagnetic lock are installed with the possibility of interaction with the part of the stem associated with the movable gripper. In addition, the loading device is made in the form of an electromagnet with external measles which is rigidly connected with the rod. Figure 1 shows the stand, side view; 2 shows a separator coupling; in FIG. 3 a locking device and an electromagnetic lock. The stand contains a frame T, a fixed gripper 2 mounted on it, a locking mechanism placed in a single body 3, made in the form of 3 balls with springs 5 located in the holes of the body, 6 rocker arms 6, one ends of which are installed with the possibility of interaction with balls k, and on the housing 3 with the ability to interact with the second ends of the rockers 6 of the nut 7, and the electromagnetic lock 8 with the movable element 9. The stand also contains an adjustable stop 10 placed on the base 1, a movable gripper 1, a rod consisting of two Parts 12 and 13j are connected by a separating coupling, made in the form of levers 1§ and 15, mounted on part 12 of the rod, connected to a movable gripper 11 and interacting with the balls 5 of the stopper mechanism, with the possibility of their ends interacting with an adjustable stop 10 TB and pins TB with spring 17 interacting with the second ends of the levers It and 15 and installed. On part 13 of the rod. In addition, the stand contains an axis 18 with a spring 19 installed in the stem part 12 with the possibility of interacting with the movable element 9 of the electromagnetic lock 8, a loading device made in the form of an electromagnet 20 mounted on the base 1, the outer shaft 21 of which is rigidly connected with the end hour These are 13 rods, and a system of 22 measures of forces and deformations. 9 The stand works as follows. zom. Fix the specimen 23 in the fixed gripper 2 and the movable gripper 11 and set the adjustable stop 10 so that the distance between it and the ends of the levers 14 and 15 is equal to the specified deformation of the specimen 23. The electromagnet 20 is turned on, which attracts the bore 21 with the stem. Sample 23 is not stretched, since the rod is locked by a clamp 8. After the value of the electromagnetic force in the electromagnet 20 reaches its maximum value, include a clamp B, the movable element 9 of which acts on the axis 18 and releases the rod, which | 5 | Moving, stretches sample 23. When the rod is moved, the ends of the levers It and 15 abut against the adjustable stop 10, rotate, press the pins 16 and separate the parts 12 and 13 of the stem from each other. Part 13 moves further until the end of the course of the outer core 21 of electromagnet 20, and part 12 tends to move in the other direction under the action of elastic forces of sample 23. The balls 4 are wedged between stem part 1.2 and body 3 and fix stem part 12 and sample 23 in stretched to specified deformations. state, the force acting on the specimen 23 is measured, and its deformation at the moment of stock jamming and using these values obtained at high loading rates, the value of the instantaneous modulus of elasticity is calculated. Measure force and strain--. sample at a given time after loading, record the change in the value of the modulus of elasticity depending on the time of loading. After completing the measurement and testing, turn off the electromagnet 20 and connect both parts 12 and 13 of the rod. Then the nut 7 is turned until it interacts with the ends of the rocker arms 6, which push the balls k and release the rod. The proposed bench makes it possible to determine the values of the instantaneous modulus of elasticity in viscoelastic materials by using an electromagnet as a loading device and an automated system for separating the rod and fixing the sample, as well as the value of high velocities of the original deformation of the sample material and eliminate the dynamic effects on the sample. Claim 1. A test stand for tensile testing of material samples containing a frame and fixed clamping devices mounted on it, a loading device, a locking mechanism and an adjustable stop, a moving gripper and a rod, one end of which is connected to the loading device and the second - with a movable gripper, which is characterized by the fact that, with the aim of improving accuracy in determining the instantaneous modulus of elastic materials, it is equipped with an electromagnetic lock placed on the frame, the rod is made and two parts interconnected with the help of separator E5 15 20 of the Ea muff, made in the form of levers mounted on one part of the stem with the possibility of interaction with an adjustable stop, and spring-loaded pins placed on the second part of the stem and interacting with the levers, and the stopper mechanism and an electromagnetic lock is interlocked with a portion of the stem associated with the movable gripper.

2. The stand according to claim 1 is also distinguished by the fact that the loading device is made in the form of an electromagnet, the outer bark of which is rigidly connected to the rod. Sources of information taken into account during the examination 1. USSR Author's Certificate No., cl. G 01 N 3/00, 1969 (prototype).