K. Jamroziak

Critical to Quality Factors of Engineering Design Process of Armoured Vehicles

Critical to quality factors of engineering design process of armored vehicles includes establishing the effects that defects have on the quality of mechanical objects as per engineering assessment criteria. Determination of the factors is an original part of work known as the Optimal Design For Six Sigma [9], which defines a defect as an inconsistency between parameters and the technical specification limits of the mechanical object. The basis for determining the common factors of the effects of defects is established through conducting surveys among users and establishing the significance of the engineering assessment criteria. Innovative product design based on the measurable quality factors and crucial for customers allows effective optimization of the object, and the ability to achieve a stable and optimal degree of product quality. In effect, this method enables to limit the occurrence of defects through preventive actions.

Analysis of Material Punching Including a Rotational Speed of the Projectile

Materials used for the construction of ballistic shields are characterized by a variety of behaviours under the influence of external loads. Ballistic impact (by a bullet) in armour (ballistic shield) is an example of the phenomena that could be considered in the category of a dynamic load caused by the strike of the mass. Computer simulations are commonly used in such situations. It is especially important to adopt a proper model of the behaviour of the material. This paper presents the results obtained by simulating free 3D points and using the application developed by the authors for the purpose of this research. The made calculations include the translational motion and rotary motion of the projectile as well as the stiffness of the material, the damping of the material, friction at the points of contacting surfaces, viscous friction and plastic deformation (the material beyond the plastic yield point is perfectly plastic). The results of simulations were validated with experimental research.

The Method of Determining Certain Parameters of Energy Absorption in Materials Under Complex Dynamic Excitations

The paper presents the method to identify the dissipative properties of the materials with a clear hysteresis loop under the quasi-static loads. Because of the fact that for low values of velocity, the resisting forces related to the speed are minimal, it is not possible to determine these forces as the functions of velocity in the quasi-static deformations. It results in the need to develop such methods for identification, which use the responses of the tested system to the cyclic loading with a high frequency. This paper presents such a method. Its application may be useful in the area of constructing the effective and modern ballistic shields.

Calculations with the Finite Element Method During the Design Ballistic Armour

For protection against projectiles with higher impact speed (up to 1000 m/s) a type of a ballistic sandwich shield can be used—which is a monolithic combination of ballistic laminates with additional materials, typically hard layers made of ceramic in the form of plates or spheres of oxides, carbides and nitrides. The authors of this paper, by using FEM to optimize defined material sets to fire the cartridge 7.62 × 54R mm, give a range of results which are compared with tests of ballistic firing on the shooting range.

Chosen Problems of Selection the Basic Chassis for the Special Purpose Body

The chosen problems of selection the basic chassis for special purpose body are presented in the paper. The technical data of chassis have to go through various tests, most often within the proving ground tests. The paper contains the analysis of chosen tests and their usefulness in the design process of special purpose vehicle.

Parametric Identification of the Degenerate Model with a Dissipative-Elastic Element Dispersing Impact Energy

The article discusses the issues regarding the identification process of the ballistic impact on a shield of composite construction. Using a mathematical model of the phenomenon of piercing the material with a bullet fired from a firearm, it has been assumed that the resisting force F of the material is described by a non-linear function consisting of the elastic element and the dissipative element. Identification equations have been derived for specific structures of the model. The studies related to the response of the model to pulse load have been conducted by numerical simulations the results of which have been verified by the tests conducted in a shooting range.