These joints are used when the designer and contractor anticipate difficulties during the construction of overlap joints. They were not included in the PN EN 1993‒1‒8 in full scale. Resistance assessment of such joints is presented in accordance with standard rules. The results were compared with the experimental studies carried out at the “Mostostal” Centre; while the former research activities and the legitimacy of the proposed method of assessing the resistance of these joints was confirmed. This is an example of an overlap joint calculation.

This paper presents a vibration analysis of a multi-link surgical micromanipulator joint, based on its detailed mathematical model. The manipulator’s prototype contains 6 links with the diameter of 8-10 [mm] and with the length of the modules of about 130 [mm]. It is driven by brushless servomotors with worm and planetary gears, for which the total transmission ratio is above 1/10000. Regarding the low efficiency of micro-robot drive systems and its vibrations, a reliable joint model and its performance is crucial for the development of a high-precision control system. To achieve the required accuracy, modelling framework has been enriched with an advanced model of friction. Simulation results are presented and discussed.

Introduction: Arthrocentesis has been used in the temporomandibular joint (TMJ) to analyze components of the synovial fluid or as a therapeutic procedure associated or not with the admini- stration of a drug. The rabbit is one of the most commonly used animal species as a model for pathologies that affect the TMJ. The aim of this study was to propose a specific technique to perform arthrocentesis on the rabbit TMJ, emphasizing descriptions of reference points and measurements for a successful puncture without complications. Materials and methods: Fourteen adult rabbits (Oryctolagus cuniculus) were used. The project was approved by the Scientific Ethics Committee of the Universidad de La Frontera (File Nº083/2016). Results: The description of the technique was divided into three steps: 1) Location of the rabbit TMJ, 2) Positioning of the needles in the TMJ, and 3) Passage of fluid through the TMJ. Conclusions: This arthrocen- tesis technique could help to simplify the procedure and give the investigator a guide for joint washing and extraction of synovial fluid in the rabbit TMJ.

A “rock bridge”, defined as the closest distance between two joints in a rock mass, is an important feature affecting the jointed rock mass strength. Artificial jointed rock specimens with two parallel joint fractures were tested under uniaxial compression and numerical simulations were carried out to study the effects of the inclination of the rock bridge, the dip angle of the joint, rock bridge length, and the length of joints on the strength of the jointed rock mass. Research results show: (1) When the length of the joint fracture, the length of the rock bridge, and the inclination of the rock bridge stay unchanged, the uniaxial compressive strength of the specimen gradually increases as the inclination of the joint fracture increases from 0° to 90°. (2) When the length of the joint fracture, the length of the rock bridge, and the inclination of the joint fracture stay unchanged, the uniaxial compressive strength of the specimen shows variations in trends with the inclination of the rock bridge increasing from 30° to 150° (3). In the case when the joint is angled from the vertical loading direction, when the dip angle of the joint fracture, the inclination of the rock bridge, and the length of the rock bridge stay unchanged, the uniaxial compressive strength of the specimen gradually decreases with an increasing length of joint fracture. When the dip angle of the joint fracture, the inclination of the rock bridge, and the length of the joint fracture stay unchanged, the uniaxial compressive strength of the specimen does not show a clear trend with an increase of the length of the rock bridge.

This paper presents an approach based on NURBS (non-uniform rational B-splines) to achieve a seismic response surface (SRS) from a group of points obtained by using an analytical model of RC joints. NURBS based on the genetic algorithm is an important mathematical tool and consists of generalizations of Bezier curves and surfaces and B-splines. Generally, the accuracy of the design process of joints depends on the number of control points that are captured in the results of experimental research on real specimens. The values obtained from the specimens are the best tools to use in seismic analysis, though more expensive when compared to values simulated by SRSs. The SRS proposed in this paper can be applied to obtain surfaces that show site effect results on destructions of beam-column joint, taking into account different site conditions for a specific earthquake. The efficiency of this approach is demonstrated by the retrieval of simulated-versus-analytical results.

This article deals with the problem of determining the resistance of end-plate connections. A nonlinear FEM model of the joint was constructed in order to predict its carrying capacity. A standard code procedure was done as well. The analyses have been done to assess atypical end-plate joints designed and constructed as a part of roof structures.

A speaker recognition system based on joint factor analysis (JFA) is proposed to improve whispering speakers’ recognition rate under channel mismatch. The system estimated separately the eigenvoice and the eigenchannel before calculating the corresponding speaker and the channel factors. Finally, a channel-free speaker model was built to describe accurately a speaker using model compensation. The test results from the whispered speech databases obtained under eight different channels showed that the correct recognition rate of a recognition system based on JFA was higher than that of the Gaussian Mixture Model-Universal Background Model. In particular, the recognition rate in cellphone channel tests increased significantly.

The paper presents the results of research on the modification of the face geometry of the refill friction stir spot welding tool sleeve for welding thin aluminum sheets with an Alclad and an oxide anode coating. The analysis of the impact of such modification on the process perform (tool motion parameters, temperature) and microstructure as well as mechanical strength of the lap joints were analyzed. The tests were carried out using aluminum alloy 2024-T3 sheets with thickness 1.27 mm. For comparative purposes, joints were also made using plates without an Alclad and without anodized coating with using unmodified tool and modified tools with developed 3 variants of face geometry. The samples with the joint were subjected to metallographic and strength tests. It has been shown that the use of modified geometry has a decisive influence on the performance of the process and the effect of softening and mixing of materials in the zone of point connection.

A numerical analysis of the initially clamped bolt joint subject to the working pressure is presented in the paper. Special, hexahedral 21- and 28-node isoparametric finite elements have been employed to model the contact zone. In this model, one takes into account loading due to the working pressure in the gap between the gasket and the flange arising as an effect of the progressing joint opening, what has not been considered in recent papers. Nonlinear stiffness characteristics of the bolt and the flange with the gasket are developed. Working pressure corresponding to the critical bolt force resulting in the joint leakage (complete opening between the gasket and the flange) is determined. FE computational results are compared with the available experimental results. The numerical results are presented using the authors' own graphical postprocessor.

Introduction: Temporomandibular disorders (TMD) are the second most common cause of chronic pain in the human musculoskeletal system. The triad of symptoms of TMD includes: pain within the temporomandibular joint (TMJ), limitation of its mobility and crepitations. The aim of the study was to present the methods of physiotherapy and to assess its effectiveness in patients with hypomobility of temporomandibular joints.

Material and Methods: 44 patients (40.2 ± 10.6 years) were examined for signs of TMD using the Manual Functional Analysis of masticatory system (MFA) questionnaire due to DC/TMD. In the above group, 20 patients showed hypomobility of TMJs and myofascial pain. They underwent a 3-week phy-siotherapy consisting of manual therapy and exercises. In the study group, linear measurements of TMJs mobility and palpation of selected masticatory muscles were performed. Pain was assessed before and after 3 weeks of therapy according to Numerical Rating Scale (NRS). Statistical processing of the data was done with STATISTICA 13 and was conducted considering significance at a p-value <0.05.

Results: Significant improvement in TMJ’s mobility, which increased on average by 6.6 mm (p = 0.0005) and reducing of pain, a decrease of 3 points on average on the NRS Scale (p = 0.00002) were achieved.

Conclusions: The applied physiotherapy algorithm, including manual therapy and exercises of mas-ticatory muscles, is effective in the case of improvement TMJ’s range of motion and reduction of pain in patients with hypomobility of TMJ’s.

About 1600 joint fractures were measured in tillites of the Upper Hecla Hoek Formation on the southern shore of Bellsund. Measurements were collected in 12 areas between the Renardbreen and Tjörndalen. Ray diagrams and contour diagrams of joint fractures, and contour diagrams of joint fractures after rotation to pre-folding position were made for each area. The preliminary analysis of diagrams indicates 2 conjugated joint sets: ca. 60°—120° and 0°—30°. This joint system is probably older than folding and was originated under ENE—WSW to NE—SW stress.

The problem of uniqueness and representativeness of steel frame fire resistance assessment is considered in this paper. The thesis, that the selection of analysis method determines the result in both qualitative and quantitative terms is given scrutiny. It is also shown, that the differences between computed values may be significant. The selection of an appropriate computational model for an analysis of this type seems to be especially important, as the possible overestimation of the fire resistance determined during computation is equivalent to an unjustified optimism of the user with respect to the safety level warranted. In the considerations presented here the critical temperature determined for the whole bearing structure is considered as the measure of sought resistance. The determined temperature is associated with the bearing structure reaching the bearing capacity limit state subject to fire conditions, treated as accidental design situation. Two alternative computational methods have been applied during calculations: the first one – classical, based on 1st order statics and using the buckling length concept for members of the considered frame, and the second one – taking account of 2nd order phenomena via simple amplification of the horizontal loads applied to the frame. Special attention has been paid to the influence exerted on the final fire resistance of the considered structure by the real joint rigidity, decreasing with increasing temperature of the structural members. The obtained results differ not only in the value of determined temperature but also in the indicated location of the weakest frame component, determining its safety.

This elaboration presents the method of virtual positioning of the construction of an endoprosthesis of hip joint in a patient’s pelvis and femoral bone, reconstructed on the basis of imaging obtained from computer tomography. It is based on the matching of an implant to individual anatomical-biomechanical conditions. The method is established on the following procedures: diagnostic, spatial modeling, virtual measuring and targeted biometrological application for the model of bone structures. The final effect of the completed procedures is selection and optimal positioning of the endoprosthesis of hip joint before a planned medical intervention. The determined geometrical parameters of bone structures and settled positioning of the endoprosthesis can create data for the system of computer navigation.

This paper proposes an analysis of the effect of vertical position of the pivot point of the inverted pendulum during humanoid walking. We introduce a new feature of the inverted pendulum by taking a pivot point under the ground level allowing a natural trajectory for the center of pressure (CoP), like in human walking. The influence of the vertical position of the pivot point on energy consumption is analyzed here. The evaluation of a 3D Walking gait is based on the energy consumption. A sthenic criterion is used to depict this evaluation. A consequent reduction of joint torques is shown with a pivot point under the ground.

In the present work, a constitutive model of materials undergoing the plastic strain induced phase transformation and damage evolution has been developed. The model is based on the linearized transformation kinetics. Moreover, isotropic damage evolution is considered. The constitutive model has been implemented in the finite element software Abaqus/Explicit by means of the external user subroutine VUMAT. A uniaxial tension test was simulated in Abaqus/Explicit to compare experimental and numerical results. Expansion bellows was also modelled and computed as a real structural element, commonly used at cryogenic conditions.

The paper presents a dynamic analysis of the damaged masonry building repaired with the Flexible Joint Method. Numerical analysis helped to determine the effect of the applied repairing method on natural frequencies as well as values of stresses and accelerations in the analyzed variants of numerical model. They confirmed efficiency of the proposed repair method.

Presented in this paper are results of an experimental investigation on the rivet flexibility and load transmission in a riveted lap joint representative for the aircraft fuselage. The test specimens consisted of two aluminium alloy Alclad sheets joined with 3 rows of rivets. Two different squeeze forces were applied to install the rivets. Rivet flexibility measurements have been performed under constant amplitude fatigue loading using several methods including two original optical techniques developed by the present authors. The axial tractions in the sheets required to determine the rivet flexibility have been derived from strain gauge measurements. In order to eliminate the effect of secondary bending the strain gauges have been bonded at the same locations on the outside and faying surface of the sheet. The experiments enabled an evaluation of the usefulness of various techniques to determine the rivet flexibility. It was observed that, although the measured flexibility was identical for both end rivet rows, the load transfer through either of these rows was different. Previous experimental results by the present authors suggest that behind the non-symmetrical load transfer distribution through the joint are large differences between the rivet hole expansion in the sheet adjacent to the driven rivet head and the sheet under the manufactured head [1]. It has been concluded that commonly used computation procedures according to which the load transfer is only related to the rivet flexibility may lead to erroneous results.