The present invention provides a method for testing a helmet that uses a risk function that incorporates both linear and rotational acceleration to predict the helmet's ability to prevent a concussion. In certain embodiments, the testing matrix includes 3 impact energy levels and 4 impact locations, for a total of 12 testing conditions per helmet.

The display panel is a display panel that is flexible, including: an EL structure layer including a plurality of EL elements arranged two-dimensionally; a foamed resin layer on a side of the EL structure layer that is opposite to a light emitting surface of the EL structure layer; a metal layer provided between the EL structure layer and the foamed resin layer; and a first adhesive layer provided between the EL structure layer and the metal layer and comprises an adhesive having an elastic modulus of 90 kPa or more.

A shock-resistance testing apparatus includes a support base, a first rotating component and a controller provided on the support base. A second rotating component is coupled to one side of the first rotating component. A testing board is placed on the first rotating component. A falling board is placed on the testing board. The controller controls the first rotating component to drive the second rotating component rotating from one side of the testing board to another side of the testing board. The controller controls the second rotating component to lift the testing board. The controller controls the second rotating component to move away from the testing board so that the testing board falls.

A shock-resistance testing apparatus includes a support base, a first rotating component and a controller provided on the support base. A second rotating component is coupled to one side of the first rotating component. A testing board is placed on the first rotating component. A falling board is placed on the testing board. The controller controls the first rotating component to drive the second rotating component rotating from one side of the testing board to another side of the testing board. The controller controls the second rotating component to lift the testing board. The controller controls the second rotating component to move away from the testing board so that the testing board falls.

A method for testing a helmet for effectiveness of user protection includes moving a load along a predetermined path, supporting a target body at an impact location in the predetermined path, the target body including a head model and a helmet disposed on the head model, and impacting the target body with a force generated by the moving of the load. The impacting of the target body entails contacting the target body with an impactor free to move perpendicularly and tangentially relative to a surface of the target body. The supporting of the target body is at least reduced, if not eliminated, before or during the impact of the impactor with the target body at the location. Forces generated are automatically measured or sensed during the impact of the impactor with the target body at the location.

The present technology provides an impact test device and method. The rotational speed of a rotary drum with a rubber sample attached on the outer surface is set to a desired rotational speed, the impact cycle for the surface of the rubber sample of the contact member by the repeat-impact mechanism is set to a desired cycle, the impact load by the contact member is set to a desired impact load by a weight member, a desired contact member is selected from among the plurality of contact members with different specifications, and the contact member is repeatedly made to collide with the surface of the rubber sample by rotating a vertical excitation roller and pivoting the arm portion in the vertical direction with a rotation shaft.

The present technology provides an impact test device and method. The rotational speed of a rotary drum with a rubber sample attached on the outer surface is set to a desired rotational speed, the impact cycle for the surface of the rubber sample of the contact member by the repeat-impact mechanism is set to a desired cycle, the impact load by the contact member is set to a desired impact load by a weight member, a desired contact member is selected from among the plurality of contact members with different specifications, and the contact member is repeatedly made to collide with the surface of the rubber sample by rotating a vertical excitation roller and pivoting the arm portion in the vertical direction with a rotation shaft.

A deformation mode analysis method for a member of a structure is a method of analyzing a deformation mode of each member by performing structural analysis or a structural test on a structure including a single member or a plurality of members. In this method, the deformation mode of the structure is analyzed by separating the structure into a plurality of regions and calculating deformations for every separated region.

A method of detecting a preload of a linear guide includes: applying an external force to the linear guide with an external force applying device, wherein the external force applying device sends an impact signal while applying the external force; sensing with a sensor a vibration signal sent from the linear guide because of vibration thereof which occurs under the external force; and receiving the impact signal of the external force applying device and the vibration signal of the sensor and calculating the preload of the linear guide according to a received result, with a signal analyzer. Therefore, with the method of the present invention, the preload of the linear guide is precisely tested regardless of environmental factors.

The invention relates to a load simulation test stand having at least one hydraulic test cylinder (1) which comprises at least one cylinder chamber (1a, 1b) which can be charged with hydraulic fluid, preferably two cylinder chambers (1a, 1b) which can be charged with hydraulic fluid and which act counter to one another, in the case of which load simulation test stand the at least one test cylinder (1), in particular each of multiple provided test cylinders (1), comprises at least one capacity element (5, 6, 7), preferably a capacity element (5, 6, 7) which is exchangeable or which is adjustable in terms of hydraulic capacity, by means of which the hydraulic overall capacity of the at least one cylinder chamber (1a, 1b) can be adjusted. The invention furthermore relates to a method for operating a load simulation test stand having at least one test cylinder (1), wherein the at least one test cylinder (1) is connected to a load which is to be moved, and wherein the load is moved by means of a pressure control system (4) by temporally changeable control of the fluid pressure in the at least one cylinder chamber (1a, 1b) of the at least one test cylinder (1), and wherein, for the load which is to be moved by means of the at least one test cylinder (1), in a manner dependent on the pressure control bandwidth of the pressure control system (4), the natural frequency of the unit composed of the at least one test cylinder (1) and load is set to a value smaller than the pressure control bandwidth by changing the capacity of the capacity element (5, 6, 7), preferably adjusting the capacity of the adjustable capacity element (5, 6, 7).