The paper presents 48 tests on the connections with bolts in bearing. Single bolts connections as well as the connections with up to six bolts positioned in the direction of loading were testes in order to obtain the evidence on bolt bearing deformation capacity and resistance. Several connection configurations including connection with bolts in single shear were tested. The bolt bearing resistance and the connection resistance are compared to Eurocode 3 design rules. Moreover, the numerical parametric study on 114 single bolt connections is presented. The results of the study are compared tothe Eurocode bearing resistance formula, as well as to the new bearing resistance formula that is based on the results of high strength steel bolt bearing connections.
COBISS.SI-ID: 5918561
The paper presents experiments on connections with one and two bolts made of mild steel grade S235. The results are compared with the tests on connections made of high strength steel. The test results are substantiated with numerical parametric analysis. The effect of bolt bearing is thoroughly analysed. The bearing strength at bolt holes according to standard EN 1993-1-8 is critically evaluated and a modified design check is proposed. The modified check is conceptually the same as the current one, but it is simpler, less conservative and it is in better correlation to the test results. The block shear strength and net cross-section strength are also discussed and modifications to the EN 1993 design rules are given.
COBISS.SI-ID: 6514785
The originality of this paper is in the presentation of the experimental results on tension splices in steel S690 with three or four bolts, positioned in the direction of loading. The tests were also numerically simulated to evaluate the stress and deformation state in the steel plates due to localized pressure of the bolts. It was shown that the distribution of forces between bots may be non-uniform and as such it is not included in any of the Eurocode rules. The results were compared to the Eurocode bearing resistance formula and it was proven that the bearing resistance is not properly defined and it also does not properly limit the bolt-hole deformation. Moreover, the unfavourable initial position of the bolts due to fabrication tolerances did not significantly affect the force distribution or the resistance. The new bearing resistance formula is also presented in the paper. The new formula is defined consistenly to the Eurocode and differs between failure types. It gives better results than Eurocode bearing resistance formula if compared to the test results.
COBISS.SI-ID: 5173345
The paper deals with the bearing stiffness at bolt holes. In bearing-type joints the connected plates are in contact with the bolt shank and the load is transmitted by shear on the bolts and high bearing stress in the plates around the bolt holes. A bearing stress in the material is developed due to the contact pressure. Initially, the contact area is very small, causing stress concentrations and yielding of the material at very low loads. Yielding allows embedment of the bolt on a larger contact area. Such behaviour is interpreted as nominally elastic behaviour, as stress concentrations are eliminated by yielding of the material occurring at early load stage. The behaviour of bearing at bolt holes is very nonlinear, therefore the evaluation of the bearing stiffness is not trivial. The bearing stiffness given in EN 1993-1-8 is given and compared to the test results and to the results of the numerical simulations of single bolt connections. The simple equation that defines the initial and secant bearing stiffness at bolt holes is given and applied to the test results of lap joints with one and several bolts.
COBISS.SI-ID: 6487137
The market offers new large steel angle profiles, the largest being L300/35. To check their buckling resistance, the investigation of the residual stress field is presented in this paper. Since the buckling behaviour of steel angles is significantly affected by the residual stresses, the stresses were measured on six hot rolled and two welded equal angles by sectioning method. The traditional sectioning method was improved by introducing the water jet cutting. The released deformations were measured by the strain gauges. On the basis of the statistical evaluation of the test results, the most appropriate residual stress distribution models were considered in the numerical analysis. The results of the geometrical and material nonlinear numerical analysis were equal angle buckling curves.
COBISS.SI-ID: 6545249