Showing papers on "Dynamic load testing published in 1976"
TL;DR: In this paper, a finite element technique was introduced into an integro-differential equation formulation of a shallow arch to investigate two forms of instability when subjected to a symmetric dynamic load.
Abstract: When a shallow arch is subjected to a symmetric dynamic load, this load becomes “critical” if a slight increase in the load magnitude leads to a sudden snap-through. Another form of instability occurs when a slight antisymmetric component in the load produces a sharply increasing antisymmetric response. Both forms of instability are investigated by means of a numerical procedure which introduces a finite element technique into an integro-differential equation formulation. Where applicable the results generally confirm previous results obtained elsewhere, but cover a broader range of problems and are believed to be more accurate.
31 citations
01 Mar 1976
TL;DR: In this paper, the authors present a general report on the current commonly used methods for the analysis of the Limit LOAD BEARING CAPACITY, LOAD DISTRIBUTION, and settlements of PILE GROUPS.
Abstract: IN THIS GENERAL REPORT THE CURRENTLY USED METHODS FOR THE CALCULATION OF THE LIMIT LOAD BEARING CAPACITY, LOAD DISTRIBUTION AND SETTLEMENTS OF PILE GROUPS ARE DEMONSTRATED. A SIMPLE METHOD OF CALCULATING THE LIMIT LOAD BEARING CAPACITY AND CHECKING BY MEANS OF MODEL TESTS IS DEVELOPED. THE BASIC ASSUMPTIONS FOR THE LOAD DISTRIBUTION AND SETTLEMENTS AS WELL AS THEIR DEPENDENCE ON THE VARIOUS INFLUENCE FACTORS AND THE CALCULATION TECHNIQUES AND THEIR RELIABILITY ARE EXPLAINED. THE USE OF TENSION PILES TO COUNTERACT LOOSENING OF FOUNDATION MATERIAL OF UNCONSOLIDATED SOILS AND THE DETERMINATION OF THE DIFFERENTIAL SETTLEMENT IN PILE GROUPS IS ALSO TREATED. THE SAME THEMES ARE ALSO COVERED FOR COHESIONLESS SOILS, WITH EMPHASIS ON THE SPECIFIC DIFFERENCES, SUCH AS THE COMPACTION EFFECT RESULTING FROM DRIVING NEIGHBOURING PILES AND THE INFLUENCE OF THE SEQUENCE OF DRIVING ON THE LOAD DISTRIBUTION. THE THIRD SECTION DEALS WITH STRESSES IN A PILE DURING DRIVING, INVESTIGATIONS OF CALCULATION METHODS AND COMPARATIVE MEASUREMENTS OF HORIZONTALLY LOADED PILES AND THE DEPENDENCE OF THEIR BEARING CAPACITY ON GOVERNING PARAMETERS, THE PROBLEMS ASSOCIATED WITH THE PULLING OF INCLINED PILES FOR TAKING HORIZONTAL FORCES, THE ANALYTICAL AND TEST METHODS OF DERIVING THE BEARING CAPACITY OF TENSION PILES. IN CONCLUSION, PROBLEMS OF NEGATIVE SKIN FRICTION ARE COVERED, AS WELL AS THE FOUNDATIONS OF DAMS ON PILES AND THE BASES OF THEIR DESIGN. THE COVERING ABSTRACT FOR THE CONFERENCE IS IRRD NO 306088.
8 citations
TL;DR: In this paper, a self-acting journal bearing of finite length has been analyzed in order to obtain the dynamic characteristics when an active film of a homogeneous single-phase liquid lubricant extends over the whole bearing arc span.
5 citations
TL;DR: In this article, a technique for applying a well-defined dynamic load to models for studies in dynamic photoelasticity is described, which is suited to studies where simple variation and accurate determination of the load-cycle parameters, as well as precise reproducibility are necessary.
Abstract: A versatile technique for applying a well-defined dynamic load to models for studies in dynamic photoelasticity is described. The method utilizes the shock front produced in a gas-dynamic shock tube to apply a load to models by direct normal impact. The principles and scope of the method are described and some examples of the dynamic stresses arising from shock-front impact on a low-modulus photoelastic model are presented and discussed. The method is suited to studies where simple variation and accurate determination of the load-cycle parameters, as well as precise reproducibility, are necessary. The method, in addition, permits close-field study of the initial response of materials to dynamic loading to be undertaken.
4 citations
Patent•
26 Jan 1976
TL;DR: A bearing transducer assembly for measuring the dynamic load applied to a bearing by an oscillating or rotating member is described in this paper, which includes a shaft journaled within a thin walled bearing, a support member, a plurality of transducers mounted between the support member and the bearing for supporting the bearing and shaft, and an electrical circuitry for cancelling the bearing distortion components.
Abstract: A bearing transducer assembly for measuring the dynamic load applied to a bearing by an oscillating or rotating member. The apparatus includes a shaft journaled within a thin walled bearing, a support member, a plurality of transducer assemblies mounted between the support member and the bearing for supporting the bearing and shaft and for detecting the dynamic load placed thereupon by the oscillation or rotation of the shaft, and an electrical circuitry for cancelling the bearing distortion components and measuring the dynamic load component representative of the dynamic load applied to the bearing.
4 citations
TL;DR: In this paper, a diverging duct is used to solve by Euler and wave equation for acceleration and velocity of the fluid behind the wave front, that the two-dimensional, time-dependent pressure distribution, induced by the wave propagation, can be calculated.
3 citations
01 Mar 1976
TL;DR: In this paper, the authors found that the surface strain of a Rough-Surface PILE was twice that of a SMOOTH STEEL PIPE and the surface tension was only half that of COMPRESSED PILES.
Abstract: IN SWEDEN DYNAMIC DRIVING FORMULAE ARE FREQUENTLY USED FOR THE EVALUATION OF THE BEARING CAPACITY OF FRICTION PILES IN SAND. HOWEVER, THERE IS NOT A SATISFACTORY AGREEMENT BETWEEN CALCULATED BEARING CAPACITIES AND BEARING CAPACITIES OBTAINED IN THE TEST LOADS. FOR THIS REASON THE SWEDISH COMMISSION FOR PILES IS CARRYING OUT EXPERIMENTS USING INSTRUMENTED STEEL PIPE PILES. IN ADDITION, METHODS FOR CALCULATING BEARING CAPACITY WITH THE AID OF PROBES HAVE BEEN INVESTIGATED. IN THOSE EXPERIMENTS CARRIED OUT, BEARING CAPACITY ON THE PILE TIP WAS FOUND TO BE APPROXIMATELY HALF THAT OF THE POINT RESISTANCE FOR STATIC PROBES IN LOOSE SAND. THE SURFACE FRICTION OF A ROUGH-SURFACE PILE WAS FOUND TO BE TWICE THAT OF A SMOOTH STEEL PIPE. THE SURFACE FRICTION OF TENSION STRESSED PILES WAS HOWEVER ONLY HALF THAT OF COMPRESSED PILES. THE COVERING ABSTRACT FOR THE CONFERENCE IS IRRD NO 306088.
3 citations
01 Jan 1976
TL;DR: In this article, a series of tests were carried out to determine the effect of certain factors on the load-carrying capacity of sheet-metal roofing systems subjected to repeated loading.
Abstract: The paper describes a series of tests carried out to determine the effect of certain factors on the load-carrying capacity of sheet-metal roofing systems subjected to repeated loading. The factors examined include construction factors such as fastener tightness, and design factors such as purlin thickness. It is found that all the factors affect the strength of the roof system. Safe working loads are given for certain combinations of the factors. Tests are restricted to a corrugated steel sheeting fastened to steel Z-section purlins with self-drilling self-tapping screws.
1 citations
01 Apr 1976
TL;DR: Although the tests described herein are very limited, significant information is provided regarding design loads, flexural rigidity of the armored joint system, method and spacing of anchorage, and geometry of the armament.
Abstract: This report describes the instrumentation and load testing of two different armored expansion joints. The purpose of the tests was to shed light on factors relating to the design of armored joints, and more specifically, to determine whether either of the two subject joints was underdesigned or overdesigned. Two armored expansion joints for bridges are analyzed with respect to their stress behavior under static loading. Details of the static load tests and attempts at dynamic load tests are provided. Although the tests described herein are very limited, significant information is provided regarding design loads, flexural rigidity of the armored joint system, method and spacing of anchorage, and geometry of the armament.
1 citations