Design according to Eurocode 6 in practice

The method used in Austria for calculating building heating and cooling demand is a monthly quasi-steady-state calculation. This method is presented in the European draft ISO/FDIS 13790. The simplified monthly calculation method is based on utilization factors. For these factors there is no specific mathematical derivation. The factor is based on an empirical formula. For increasing the practicability of the simplified calculation methods, the precision of the method is important, as well as the prediction accuracy by modifying the building parameters. Both requirements for a simplified calculation method are verified in this investigation. A simplified investigation of the calculation method precision for the cooling demand for offices leads to a 40 percent margin of error when using the simplified method for Vienna climate. The prediction accuracy of the monthly balanced method for changing the building parameters was verified for a six zone office model. At the end, the precision of the simplified method was quantified for an office model for the heating and cooling demand. Safety factors for the simplified method resulted from the investigation of the office model. The imprecision of the simplified method is greater than the validation of the monthly calculation method, as is exposed in the draft ISO/FDIS 13790. For the cooling demand for Vienna, the safety factor is 1.25 for the one zone method and 1.15 for the multi-zone method. For the heating demand no safety factor is necessary if the simplified method is not used for low air change rates and uncoupled models.

In the paper, a scheduling algorithm based on the estimation of packet loss amount is proposed for supporting real-time traffic in IEEE 802.22 WRAN systems. The proposed scheduling algorithm takes two steps for resource allocation. In the first step, it assigns resource to users having packets that are estimated to be dropped at next frame. In the second step, it assigns the remaining resource to the other users according to one of the existing scheduling algorithms. The simulation results show that the proposed scheduling algorithm provides much better performance than the PLFS and M-LWDF algorithm. In addition, a simple calculation method is proposed for the proposed scheme. With the simple method, we can reduce the number of checking packets in the queue as much as about a half time without any performance degradation in the case of video traffic.

Purpose. A simplified calculation method development for strengthened split cylindrical drum structures of the mine hoisting machines of the TsR-6.756.2/1.95 type. Methodology. The drum structure for the mine hoisting machines is conventionally divided into several nodes. A simplified averaged model is constructed for the nodes consisting of the shell, frontal, rib strengthening and brake discs (end nodes) based on the analysis of their operation, in particular, the stiffness analysis under different loads. After that, when assembling, the initial drum nodes are replaced with simplified ones and a so-called simplified model for the whole drum is constructed, as well as the displacements of the brake disc edges are determined. Findings. The simplified models for drum nodes have been created based on the analysis of their operation, and then the displacements of the whole drum simplified model have been calculated. Originality. The simplified calculation method error has been estimated: the method of averaging with increased thickness of the frontals. Practical value. For the TsR-6.756.2/1.95 hoisting machine with a drum diameter of 6750 mm, a drum width of 6200 mm and an adjustable part width of 1950 mm, with a groove cutting pitch of 51 mm and a maximum lifting depth of 1477 m, it has been determined that the maximum axial displacements for brake disc edges of the jammed and adjustable parts are 0.854 and 1.921mm, respectively. A simplified calculation method has been developed for strengthened split cylindrical drum structures of the mine hoisting machines of the TsR-6.756.2/1.95 type, available for use in middle-class packages such as SolidWorks Simulation.

1. To predict the depth of a scour depression at the toe of a protected concave bank of a meander in gravel-pebble channels and to determine the rate of this scouring, a simplified calculation method was developed on the basis of analyzing the results of calculation by the complete method of the Institute of Fluid Mechanics, Academy of Science of the Ukrainian SSR. 2. The main conditions making it possible to use the simplified calculation method are: disregard of the balance of the bed load and the nonuniformity of the flow in the scour depression at the protected concave bank of meanders. To perform the calculation it is necessary to have the value of the average slope of the free surface of the water on the axis of the flow, which is assumed constant during deformation of the bottom of the meander. 3. In the calculation one determines the vertically averaged velocity of the nonuniform flow u2 and the friction velocity u*2 in the scour depression, which must be compared with the friction velocity u*p corresponding to the detachment of the erosion pavement of inhomogeneous soil composing the bottom of the meander. By assigning various values of deepening of the bottom Δzb in the scour depression, one finds the value of Δzb for which scouring of the bottom ceases (u*2=U*p). 4. To check whether the calculated deepening of the bottom can occur during the duration of the calcualted flood on the basis of the value of the bed-load discharge calculated by means of Einstein's graph, the rate of deepening of the bottom in the scour depression is determined with the use of the method given in [1] for this purpose. 5. The reliability of the recommended simplified calculation method is confirmed by the results of comparing the calculated and experimental values.

Analysis of catenary action in steel beams using a simplified hand calculation method, Part 1: theory and validation for uniform temperature distribution

This study presents centrifuge model test results of the stress and deformation characteristics of earth retaining structures with sloping backfill and local loading. Transducers are used to measure the horizontal force, bending moment and lateral displacement of the wall during the test. Silty sand is selected as backfill soil. Lateral earth pressure distribution along the wall and structure deformation are continuously measured. Test results indicate that the front wall exhibit a rotation about the top movement mode and the lateral earth pressure acting on the front wall cannot be calculated via conventional theoretical methods. In addition, lateral force increases nonlinearly with depth. This effect is more evident at the lower part of the front wall, which causes the point of the application of total thrust to occur at relatively low locations. A simplified calculation method that considers wall displacement is introduced to provide a good description of lateral earth pressure and its distribution along the wall in the height direction.

Accurate calculation of the value of the core hot-spot temperature at the design stage is becoming very critical in order to ensure that hydrogen generation that can be caused by oil-film degradation at core hot-spot temperatures as low as 110-120/spl deg/C is limited. Presented are two calculation methods developed for this purpose. Results of the FEM calculation of the location and value of the hot spot temperature in cores of three-phase, three-limb cores of power and distribution transformers show excellent agreement with tested values on a number of transformers. Insight learned from this analysis was used to enhance a previously available empirical method. This simplified calculation method is appropriate for everyday use and, hence, is suitable for design calculations. This method was shown to have again very good accuracy in the range of 2/spl deg/C for most of the cases. The simplified calculation method was also shown to provide a much greater accuracy than the original empirical method.

In skyshine dose evaluation for gamma-rays, simple calculation methods are still used in many radiation facilities since various computer codes for the skyshine calculation require considerable experience and expertise to obtain reliable results. The effect of scattered radiations in ceilings needs to be considered in order to obtain reasonable results using simple calculation methods. Therefore, dose distributions on the ceiling were calculated using MCNP-4C in the geometry of the KSU experiment. The results showed that gamma-rays of 0.3MeV or less scattered inside the facility made a contribution to the dose at the ceiling position, and the dose distribution on the concrete ceiling was strongly affected by the oblique incidence on the ceiling in the case of a point source. Additional calculations confirmed that the effect of the oblique incidence depended on the thickness of the ceiling as a function of mean-free-path. It was found that the effect was expressed as a simple formula considering gamma-ray attenuation and build-up, which would be useful in the simple skyshine calculation.

Now that excitation characteristics are being made available to the application engineer, it has become increasingly important that a simple accurate calculation method be used to determine the errors. ``Inphase addition'' has all the advantages of simplicity, and, under careful analysis, it is apparent that over the normal ranges involved, the more complicated procedure of vector addition is not warranted. This simple method has been extened to cover complete curve drawing from only one calculation by a graphical process.

This paper provides a simplified analysis method and to evaluate the potential of night ventilation to save cooling energy for office buildings. Specifically, impacts on cooling energy performance are investigated for various combinations of night ventilation flow rates and duration periods. The analysis results indicate that an increase of ventilation duration period and volume rate leads to greater night ventilation benefits for dwellings located in Denver, CO. However, an increase of the ventilation volume rate above 5 air changes per hour has a little impact on cooling energy savings. When the ventilation period is short (less than 10 hours), and the flow rate is high (more than 3 ACH), the cooling energy savings from night ventilation increase linearly with the ventilation duration period length. A simplified calculation method has been developed based on the results of a series of parametric simulation analyses. Commercial building designers and operators can use the proposed simplified calculation tool to assess the effectiveness of night ventilation in reducing cooling energy use.

A simplified gross thrust calculation method was evaluated on its ability to predict the gross thrust of a modified J85-21 engine. The method used tailpipe pressure data and ambient pressure data to predict the gross thrust. The method's algorithm is based on a one-dimensional analysis of the flow in the afterburner and nozzle. The test results showed that the method was notably accurate over the engine operating envelope using the altitude facility measured thrust for comparison. A summary of these results, the simplified gross thrust method and requirements, and the test techniques used are discussed in this paper.

An elevator rope for a high-rise building is excited forcibly by the displacement of the building caused by earthquakes and wind forces. In this paper, simplified calculation method, single degree of freedom (SDOF) system, for estimating rope deflection during earthquake is presented by using building's acceleration. Finite difference analyses of rope vibration are also performed to verify the validity of this simplified calculation method. The calculated results of this simplified calculation method is in fairly good agreement with that of the finite difference analyses.

Evaluation of simplified superposition design method for composite columns

A simple method for the calculation and measurement of symmetric microstrip coupled line even- and odd-mode impedances is presented using the arithmetic mean for the even-mode impedance. The discrepancy between measured and calculated results is very small.

A simple time domain calculation method for transient heat transfer models