Discussion on the Secondary Moment of Prestressed Frame

The secondary moment of prestressed concrete frame is different from that of continuous beam. In this paper,the principle and calculation method of equivalent load secondary moment and axial secondary moment are discussed,and the infection of secondary moment in moment modulation is analyzed,together with the suggestions of moment modulation for prestressed concrete frame with adopting the total control. The suggestions would be able to distinguish the advantageous and disadvantageous effect of secondary moment. Some helpful advises for moment modulation design are given in this paper.     

Experimental Study on Moment Modulation of Prestressed Frames

Based on the experimental study of two prestressed frames in redistribution of Internal force, it can be concluded that the dominating influence factors on moment modulation are the relative height of equivalent compression zone, the secondary moment, the ratio of beam rigidity to column and development of cracks in the top of columns.The secondary moment is very important in modulation of frames. Especially, the secondary moment will governing the modulation when the relative height of equivalent compression zone is large enough.     

The Effect on the Column Moment Considering Compress of Prestressed Concrete Beam

Axial compress is produced by the tension of prestressing beam, which engenders the third moment of column. And the third moment is always ignored in design. The thesis analyses elementarily the third moment of column and finds that the third moment must be taken seriously in some condition, and it is not the same value as the manner of tensions is different . As a result, some helpful conclusion and suggestion are presented.     

Energy-momentum Tensor of Electromagnetic Field Outside Neutron Star With Magnetic Moment

The energy-momentum tensor of electromagnetic field outside the neutron star with magnetic moment is cal-cuated based on the metric tensor and 4-dimmensioal potential outside the spherical symmetric mass with magnetic moment. The numerical calculation and the distributed curve indicate that the electromagnetic energy of the magnetic-dipole will be greater in curved space-time than in Minkowski space-time.     

Several Matters to be Noticed During the Moment Modulation Design of Prestressed Concrete Frame

The moment modulation of prestressed concrete frame has some differences compared with that of continuous beam.Based on the analysis of ratio of column linear rigidity to beam one,form of load,second moment and plastic hinge in column,this paper is intended to get some helpful advise for moment modulation design.     

Stability Behavior of Shuttle-Shaped Steel Lattice Columns With Bending Moment

The stability behavior of shuttle-shaped steel lattice columns subject to combined axial force and bending moment was examined through elastic buckling analysis and geometrically and materially nonlinear analysis. Firstly, the concept of section stiffness variation ratio is proposed for shuttle-shaped lattice columns and the elastic buckling behavior is discussed. Then, the effect of bending moment on the stability behavior of lattice columns is investigated, with the emphasis on the development of axial stress, bending stress and shear stress. The influence of column component spacing and diaphragm thickness on the stability bearing capacity is also analyzed. It is shown that the elastic buckling mode of the lattice column is dependent on its section stiffness variation ratio; for lattice columns with C-shaped buckling mode, the reduction in stability bearing capacity caused by bending moment is smaller than that of columns with S-shaped buckling mode; the maximum stability bearing capacity of the lattice column can be achieved by adjusting the column component spacing, and the spacing corresponding to the maximum capacity is basically consistent with the critical spacing for transformation of C-shaped buckling mode and S-shaped mode; and it is more effective to increase the thickness of columns with S-shaped buckling mode to get larger bearing capacity.     

Suggestion for Moment Modulation of Prestressed Concrete Continuous Beams

Based on the information from China and overseas,a design suggestion for moment modulation of post-tensioned prestressed concrete continuous beams with bond has been put forth in this paper. The result calculated by the suggestion is consistent with the result of varying rigidity method.     

Bi Moment in Spacial Rod with Opening Thin Walled Section

The models,principle,deducing constitutive equation by means of variational method,and general solution are researched for bi moment in anisotropic spacial rod with opening thin walled seation.     

Mathematical Model of Bearing with Bending Moment

Based on the actual situation that there is shortage of water,existence of many dry ditches,over-use of the underground water and the water pollution in the downtown of Jiaozuo city,in this paper,with comprehensive application of the multi-eco technologies such as comprehensive water-handlings and artificial wetland water purifications,the preservative strategies for the surface water and underground water together are put forward to optimize the water cycling,which can on the one hand reduce the contradictories in the water surroundings of the downtown,and on the other hand improve the landscape of dry ditches and sunk areas.     

Analysis Theory of Unbonded Prestressed Concrete Continuous Beams

In this paper, the energy method has been used to study the change of the secondary moment of unbonded prestressed concrete continuous beams and it has been contrasted with bonded prestressed beams. The question, whether the secondary moment changes or not while loading, was answered. It shows that the primary secondary moment does not change when increment method is adopted to study the beams, but the total secondary moment will change while the force in prestressed reinforcement changes.     

Experimental Investigation of "Column with Weaker Beam" Frame and "Column with Equally Strong Beam" Frame

By the way of experiment and analysis of two "one story and one bay" reinforced concrete frames, namely a "beam with weaker column" frame and a "column with equally strong beam" frame, the features of internal force redistribution are investigated and an elementary comparison about bending moment redistribution of three kinds of frames namely the "column with weaker beam", "beam with weaker column" and "column with equally strong beam" is given. Through this comparison, the objective existence of such "three kinds of frame" is proven, the moment redistribution is different for each frame and for the moment modulation, the elastic moment diagram and the difference of the internal force redistribution in different frames should be considered together.     

Experimental Study on a Prestressed Frame of Two Spans Under Unsymmetric Load

By the experimental study on a full-dimensioned prestressed frame of two spans, the relative factors are analyzed such as relative height of equivalent compression zone in critical section, secondary moment, ratio of beam rigidity to column and development of cracks in the top of columns etc., which influence the moment distribution of the post-tensioned prestressed concrete frame from the side of internal force redistribution. It is believed that that the factors of relative height of concrete equivalent compression zone and secondary moment influence the moment modulation in most degree, and ratio of column rigidity to beam also plays a part in the moment modulation to some extent. Second, the plastic joints of frame with excessive spans exit in the span which endure the whole load, at last the whole frame is destroyed because of the destruction of the loading frame, the influence to the non-loading span is little.     

Design Method of Moment-strengthening on Tension Side When Load Un removed

Based on the linear strain distribution assumption, strain development of tensile bars and ultimate moment capacity of strengthening section, which strengthened on tension side with service load un removed, is investigated. It is showed that the higher the service load bending moment to original moment capacity ratio M 1k /M u1 is, the smaller the tensile strain of strengthening re barsis, and the more the amount of strengthening re barsis, the smaller the tensile strain of original re barsis. It also showed that,When original re bar area is relatively small and strengthening re bar area is adequate, both original and strengthening re bars may get yielded and a great increment in section moment capacity is achieved, even though the ration M 1k M u1 has a relatively high value.     

A NEW METHOD BY USE OF MASS AND ACCELARATION PARAMETERS FOR BALANCING THE SHAKING MOMENT OF ARTICULATED MULTI-BAR LINKAGES

In this paper,a new method with general purpose ispresented for balancing the shaking moment of articulated multi-barlinkage.The concept of this method is clear.The moment equation oflinkages is easy to establish and solve.Furthermore its pattern structuremakes it convenient to be programmed.     

A new measurement method for mass property parameters

Mass property parameters (mass, center of mass, moment of inertia) are important technology parameters of aircraft. The traditional mass and center of mass measurement uses centroid units, and the moment of inertia measurement torsion units, which can only get results in installing direction. Because of the structural reasons, there is a need to get all high accurate physical parameters in clamping once. To solve this problem, this study merges centroid units and torsion units into one composite unit, installs a table which can tilt and rotation to measure the moment of inertia in different conditions. The moment of inertia and product of inertia relative to three axis are calculated by the method of coordinate transformation. Measurement theory of mass, center of mass and mass moment of inertia are described, the main reason of causing measurement errors is discussed, and the measurement accuracy affected by tilt error is analyzed.     

Calculating the Support Reaction Increment''s Correlation Equation of R.C Continuous Beams

According to the hypothesis of plain section and the equation of moment versus curvature of R.C section, the elastic-plastic response of pressed continuous beams is analyzed with CDC-method. The correlation equation of support reaction increment and displacement increment is induced through the relation of moment increment and curvature increment,and the adjustment value of support reaction increment of continuous beams is determined by solution of linear equation systems,which provides a rule the support reaction to follow. It can roundly and quantificationally display the moment redistribution behavior of continuous beams. A case of 4 spans continuous beam shows a high calculation rate and precision of this method.     

Evaluation of Brassica genotypes for resistance to shatter. I. Development of a laboratory test

Summary A new test procedure for measuring shatter-resistance of siliquae of Brassica spp. is described. A siliqua with its proximal end clamped is loaded as a cantilever in a testing machine. The maximum bending moment, the corresponding stiffness and the energy to cause the siliqua to rupture were taken as measures of the resistance of the siliqua to shatter. Studies showed that ranking of accessions based on either bending moment or energy closely approximated the rankings based on observations of field shatter. A reasonably high significant negative correlation was found between percentage of shattered siliquae and both bending moment and energy (r=–0.595 and –0.531 respecitvely, P=0.001). The above results indicated that bending moment and energy could be used as criteria in evaluating rapeseed genotypes for shatter-resistance in breeding programmes.     

EXPERIMENTAL RESEARCH OF THE MOMENT MODULATION INFLUENCE ON CRACKING AND DEFLECTION OF CONTINUOUS REINFORCED CONCRETE BEAMS UNDER SERVICE LOADS

Through the static tests of five two-span continuous beams with a relatively small steel ratio, the regularity of redistribution of internal forces of continuous beams with moment modulation is studied, and the moment modulation influence on cracking and deflection of continuous reinforced concrete beams under service loads is analyzed in detail. The conclusions obtained may be used as reference materials for drafting of design code considering redistribution of internal forces.     

Technical Economy Analysis on Selection of Structure About Soldier Pile

Based on silt geological condition, aimed at cantilever pile and pile-anchor, using method of beam on elastic foundation ,through multiple combinations of pile spacing, diameter, embedded-depth at different levels of excavation depth, the impaction is discussed on the greatest displacement, maximum bending moment, the largest shear forces of supporting structure, and in different excavation, bolt locations impact on maximum horizontal displacement, the greatest moment of medial and lateral bending moment, the biggest shear force of pile and the axial force of bolt. By deformation control standards of supporting structure, the law and technically feasible program is found. Then combined with construction method of pile and current quota, technical economy is performed to find the economic plan and give suggestion to the project.     

Dynamic Response Analysis of High-rise Pile Cap-soil-structure under the Wave and Earthquake Action

Finite element software was used to simulate the internal force and deformation of high-rise pile cap-soil-structure under the wave and earthquake action. Meanwhile, wave force was calculated by using Morison equation, and the mechanical behavior of structure was simulated by inputing horizontal El-Centro wave. Then, the initial state and the state of the largest positive and negative acceleration were selected to study the structure according to the time history curve, and the displacement, bending moment, shear and axial force changes of pile foundation under wave and earthquake action were discussed, which was compared and analyzed with the structural response under the action of earthquakes solely. The result shows that the moment of front row of piles is biggest, and the force of pile bolck is the most dangerous; the axial force of the corner piles is the largest, and one of the center piles is the smallest under the action of wave and earthquake. When the wave forces and seismic forces are in the same direction, the displacement, moment, and shear force of pile bolck will be increased, on the contrary, the displacement, moment, and shear force of pile bolck will be decreased.