Eugeniusz Rusiński

Superelement-based modeling of load distribution in large-size slewing bearings

The supporting structures in large-size slewing bearings are highly flexible. In order to choose the proper bearing and shape the load-carrying structure one must estimate the distribution of forces among the individual rolling elements. Advanced numerical models are needed for this. An original method of modeling the rolling element-track system is presented and its usefulness for modeling large-size bearings is demonstrated. The results of an exemplary analysis are presented in the form of graphs and figures. The superelement-based discrete bearing models are so far most comprehensive and take into account all the phenomena involved in the bearing-supporting structures system. The application of the finite-element method and the models based on the track-rolling element-track superelement made it possible to determine the effect of the deformability of the supporting structures and the nonuniformity of their flexibility on the loading of the rolling elements in the two-row bearing. The use of formulas which do not take into account the flexibility of the supporting structures to determine the distribution of the load among the rolling elements is unacceptable.

Caterpillar drive shaft damage causes analysis

The paper presents examples of fatigue stress fractures of quarry equipment drive shafts. In order to determine the real cause of this damage, we have performed a detailed analysis of the problem The paper presents the experimental data, numerical analysis and metallographic examination.

Proactive Condition Monitoring of Low-Speed Machines

This chapter represents the principle of proactive approach in condition monitoring (CM) with a focus on low-speed machines. Comparison is made to the standard recommendations for CM, and the weak points of this approach when dealing low-speed machines are highlighted. The theory of a new concept for proactive CM is given.

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.

Structural Modifications of Excavator’s Bucket Wheel by the Use of Numerical Methods

In this paper the character of loads exerted on bucket wheel was evaluated. The places of maximal stresses were determined by using finite element analysis. After this operation, a new wheel hub design was initiated. The first phase was related to development of new conceptions of the hub. The proposed conceptions were rated with respect to mass and total length of welds. This procedure led to selection of the most suitable design, which was optimized in order to minimize stress. The work at this stage consisted of continuous modification of the geometrical form, meshing of finite element model and structural analysis thereby providing information about stresses and deformations. The workmanship of the structural component and welded joints were defined according to DIN 22261 2:2006 standard.

Damage in the complex low-cycle fatigue

A life prediction approach for a random multiaxial fatigue is proposed in the present paper. D16T aluminium alloy were tested under non-proportional loading (tension-compression, torsion). Cylindrical specimens were tested under different stress controlled trajectories in the plastic range. In additional, numerical method analysis such as finite method – FEM were used in the experiment. The additional damage energy for Al alloy D16T in the middle stabilized (average) cycle during low cycle fatigue for complex non-proportional loading square trajectory was also discussed in relation with fatigue life prediction. The aim of this paper is to examine the non-proportional low cycle fatigue life of D16T aluminium alloy which shows small additional damage stress, and also develop energetically damage model for complex non-proportional stress state during low-cycle fatigue for construction.

Numerical and Experimental Analysis of a Truck Frame

Calculating the stress level of the load-carrying structure of a vehicle’s frame based on data obtained from literature can be unreliable. It is crucial to know the operating characteristics of a given vehicle. In the presented example, it was necessary to understand the phenomena that occur during operation of a vehicle, which could not travel a selected test distance without sustaining damage to the load-carrying structure. Attempts to improve the structure based solely on the analysis of damage did not bring satisfactory results. Only after performing numerical simulation of vehicle operation and an in-depth analysis of the problem was it possible to modify the frame so that it would pass the roadworthiness tests and qualify for registration.

Maintenance Management and Applied Strategies

This chapter describes the basics of maintenance management systems and key factors for successful organization and performance. It also points out the main characteristics of major maintenance strategies with their advantages and disadvantages.

Introduction—Review of Today’s Industry and Role of Condition Monitoring

Brief review of the condition, the new developments and trends in industry and related researches is given. Difference of today’s maintenance process and system with the adequate systems only a decade ago is given appointing to the fast-growing demands and responsibilities. The main reasons for the development of separate condition monitoring systems for low-speed machinery are given. A short intro of the contents of next chapters is also given.

Analysis of the Fatigue Fractures in the Eccentric Press Shaft

The paper presents selected aspects of stress analysis of eccentric press. This approach is based on the assumption that fractures can be present in the analyzed constructions. Calculations define the current state of the component with respect to fracture mechanics. Reported research work was performed using analytical, numerical and experimental methods in order to evaluate durability of the considered structural element.