Assembly Load Research Articles

Assembly Accuracy Analysis Method Based on Multi‐Stage Linearized Contact

ABSTRACTPrecision improvement in mechanical manufacturing faces challenges due to nonlinear effects impacting assembly accuracy analysis models. An assembly accuracy analysis method based on multi‐stage linearized contact is proposed to address this issue. A model of part surface asperities considering morphological errors is established using the linear superposition of discrete cosine transform (DCT) kernel functions and the assembly interface is simplified. By employing homogeneous coordinate transformation (HCT), the prediction of the part's pose during the assembly process with the rigid body assumption is achieved. The elastic contact process is divided into multiple stages according to the order of the asperity participating in the contact and further subdivided into several linear processes by adding nodes at each stage. The relationship between the assembly load and the deformation amount is established based on the related theories of contact mechanics and the geometric relationship between the assembly interfaces, thus enabling the prediction of the part's pose during the assembly process. Taking a multi‐way hydraulic valve as an object, by comparing the accuracy of pose prediction of the algorithm before and after adding nodes, it is proved that the proposed method can significantly improve the precision of assembly accuracy analysis.

Design of in-vessel mirror of ITER poloidal polarimeter

Diagnostics in-vessel mirrors receive high neutron heating loads and high radiation heat loads because it directly faces the plasma. The in-vessel mirror of this study consists of three layers; tungsten mirror, copper-alloy heatsink and stainless-steel mirror mount. The copper-alloy heatsink is actively cooled by cooling-water pipe. The tungsten mirror is attached to the heatsink with contact pressure of 3.5 MPa and is cooled by thermal conduction to the heatsink. The mirror is not rigidly fixed to the heatsink but is able to slide on the surface of the heatsink because thermal stress in the dissimilar materials during baking needs to be avoided. The structural integrity was evaluated according to RCC-MRx code. The highest primary load to the mirror was the acceleration load during plasma disruption, and the highest secondary load was the baking temperature (240 °C). All design criteria specified in RCC-MRx code are satisfied. In addition, the design of the in-vessel mirrors was developed to facilitate adjustment of mirror angle with accuracy of 0.1° A prototype mirror was made to confirm the surface deformation owing to the assembly load. Surface deformation was 6.3 μm and was sufficiently small compared to the laser wavelength.

Feasibility of winter construction for prefabricated subway station: Waterproof performance analysis of composite cross-section gasket treated by low temperature

The construction of prefabricated subway stations in northeastern China necessitates a focused investigation into the behavior of composite cross-section gaskets with ethylene propylene diene monomer (EPDM) and water swelling rubber (WSR) under low-temperature conditions. This research conducted experimental and numerical studies to analyze the mechanical and waterproof properties of WSR-EPDM gaskets treated at low temperatures. The mechanical properties were evaluated through hardness and compression tests at various treatment temperatures. Additionally, the study examined the impact of treatment temperature and loading rate on the load-deformation relationship. Then, finite element (FE) models were developed and validated based on mechanical experimental results of the gasket-in-groove system under various low-temperature conditions. Subsequently, the nonlinear FE model was used to analyze the effects of joint offset and opening angle on assembly load and waterproof performance. The results demonstrated a direct correlation between the treatment temperature and the Shore hardness and assembly load of the WSR-EPDM gasket. Lower treatment temperatures led to higher hardness and assembly load. Notably, at temperatures below −10 °C, the loading rate had a more pronounced effect on the assembly load. Furthermore, the assembly load initially decreased and then increased with an increase in joint offset, while it consistently decreased with a larger opening angle. Additionally, as the treatment temperature decreased, the average contact pressure during operation also decreased. The influences of joint offset and opening angle were negligible when the treatment temperature was below −20 °C. However, the coupling influence of offset or opening angle and treatment temperature on the waterproofness is evident for a treatment temperature between 0 ∼ −15 °C. In summary, this study serves as a useful reference for evaluating the waterproof properties of these gaskets in low-temperature environments.

Analysis of Failure Forms of Bevel Gear, Shaft, and Bearing Structure System Considering Multi-Mode Damage Accumulation

Abstract During the working process, the structural system, including bevel gear, shaft, and bearing, located in the front journal of the high pressure compressor of the aeroengine rotor is affected by various loads such as assembly load, centrifugal load, temperature load, and meshing excitation, and it leads to different modes of interface damage, for example, wear, slip, and fatigue. With the increase number of working cycles, different interface damage modes affect each other and damage gradually accumulates, which leads to the degradation of the mechanical properties of each component. Finally, the function of the weakest component is lost, resulting in the failure of the structural system. Consequently, the comprehensive influence of multiple failure forms caused by interface damage at different positions results in the failure of the structural system, where the damage position and the failure position are different, and the final failure form is uncertain. In this paper, a damage accumulation mechanical model considering multimode damage interaction is established for bevel gear, shaft and bearing structure system. And the damage-failure mechanical process of the structural system and its key influencing factors under complex environment loads are studied. The results showed that the failure forms of the structural system were closely related to the assembly and load characteristic parameters of the components. Therefore, considering the randomness of the initial assembly state and environment loads, the damage accumulation mechanical process and the final failure forms of the structural system have significant uncertainty.

Experimental study on thermo-mechanical behaviour of beam string structures

Beam string structures (BSS) have been widely employed in large-span spatial structures, while the experimental study on BSS in fire conditions is limited. This paper presents experimental investigation on thermo-mechanical behaviour of BSS with different load ratio. ISO834 standard fire and large space fire are adopted as fire conditions, respectively. The strain of BSS at high temperatures is measured by advanced strain gauges. The test results show that the prestressed string is the most vulnerable component of BSS in fire. The temperature distribution is non-uniform, and the temperature difference between the top flag and string can be up to 396.3 °C. The critical string temperature is in a range of approximate 350 °C–450 °C. Load ratio has little effect on the critical string temperature, and fire conditions with higher heating rate can increase the critical string temperature. Furthermore, the drop of residual prestress causes the rapid increase of mid-span vertical displacement and horizontal displacement. The direction of horizontal displacement of BSS without external load is outward, due to the thermal expansion. The strain distribution along the cross section indicates the additional bending moment induced by temperature. In addition, three behaviour modes of BSS at elevated temperatures are proposed according to the contribution of prestress. The behaviour modes illustrate the working mechanism of BSS as the temperature increases. Finally, a thermo-mechanical finite element model of BSS in fire conditions is established by assembly load method. The numerically predicted temperature distribution, displacement and residual prestress have a good agreement with the experimental results.

Effect of Femoral Head Material, Surgeon Experience, and Assembly Technique on Simulated Head-Neck Total Hip Arthroplasty Impaction Forces

BackgroundThere is no standard method for assembling the femoral head onto the femoral stem during total hip arthroplasty (THA). This study aimed to measure and record dynamic 3-dimensional (3D) THA head-neck assembly loads from residents, fellows, and attending surgeons, for metal and ceramic femoral heads. MethodsAn instrumented apparatus measured dynamic 3D forces applied through the femoral stem taper in vitro for 31 surgeons (11 attendings, 14 residents, 6 fellows) using their preferred technique (ie, number of hits or mallet strikes). Outcome variables included peak axial force, peak resultant force, impulse of the resultant force, loading rate of the resultant force, and off-axis angle. They were compared between femoral head material, surgeon experience level, and the number of hits per trial. ResultsAverage peak axial force was 6.92 ± 2.11kN for all surgeons. No significant differences were found between femoral head material. Attendings applied forces more “on-axis” as compared to both residents and fellows. Nine surgeons assembled the head with 1 hit, 3 with 2 hits, 14 with 3 hits, 2 with 4 hits, and 3 with ≥5 hits. The first hit of multihit trials was significantly lower than single-hit trials for all outcome measures except the off-axis angle. The last hit of multihit trials had a significantly lower impulse of resultant force than single-hit trials. ConclusionDifferences in applied 3D force-time curve dynamic characteristics were found between surgeon experience level and single and multihit trials. No significant differences were found between femoral head material.

Study on Assembly and Tensile Performance of Circumferential Anchor Joint for Shield Tunnel Considering Roughness and Size of Structure

Anchor joint is conducive to improving the automation level of the shield tunneling method, whose mechanical behavior is still not fully clear due to the complicated interaction among various structural components. In this paper, a refined FEM model is established and adopted to investigate the anchor joints' assembly and tensile performance. The operation principles of the anchor joint are first introduced for better understanding. Then, a detailed description is presented for the developed refined FEM, including the material properties, structural features, and verification. After that, 76 working conditions in total are set, and an in-depth study is conducted to examine the influence of surface roughness, gap sizes, and strength grades on the assembly and tensile behavior of anchor joints both quantitatively and qualitatively. The results show that the surface roughness mainly influences the maximum assembly load and tensile capacity of anchor joints. The gap size obviously impacts both quantitative and qualitative assembly characteristics and tensile behavior for anchor joints, whose effect is more significant than the surface roughness. The strength grade has a different influence on the distinct mechanical behavior of anchor joints. There is a positive correlation between anchor joints' assembly and tensile behavior. To satisfy the requirement of enough tensile capacity and reasonable assembly difficulty, a good solution should be to reach an appropriate balance between the assembly and tensile behavior of anchor joints.

Collaborative force and shape control for large composite fuselage panels assembly

This study proposed a force and shape collaborative control method that combined method of influence coefficients (MIC) and the elitist nondominated sorting genetic algorithm (NSGA-II) to reduce the shape deviation caused by manufacturing errors, gravity deformation, and fixturing errors and improve the shape accuracy of the assembled large composite fuselage panel. This study used a multi-point flexible assembly system driven by hexapod parallel robots. The proposed method simultaneously considers the shape deviation and assembly load of the panel. First, a multi-point flexible assembly system driven by hexapod parallel robots was introduced, with the relevant variables defined in the control process. In addition, the corresponding mathematical model was constructed. Subsequently, MIC was used to establish the prediction models between the displacements of actuators and displacements of panel shape control points, deformation loads applied by the actuators. Following the modeling, the shape deviation of the panel and the assembly load were used as the optimization objectives, and the displacements of actuators were optimized using NSGA-II. Finally, a typical composite fuselage panel case study was considered to demonstrate the effectiveness of the proposed method.

Активність і залишкове енерговиділення ядерного палива під час експлуатації і зберігання

General information on the amount of accumulated spent nuclear fuel (SNF) at NPPs in the world is presented. An analysis of the rates of SNF accumulation was carried out, and forecasts of SNF accumulation in the world and in Ukraine for the next decade were made. Information is given on the technologies for SNF handling, as well as some characteristics of SNF storage systems of wet and dry types. Radiation characteristics of SNF — radioactivity and residual energy release of nuclear fuel — largely determine both possible accident scenarios and possible radiation consequences of accidents at nuclear facilities. The article presents the results of modeling in the SCALE program code of changes in radioactivity and residual energy release of VVER-1000 nuclear fuel after period of operation of the fuel assembly in the VVER-1000 core. The model of VVER-1000 fuel assembly with 4.4% enrichment, which is used in the mode of stationary refueling, was chosen for simulation. The simulation results were compared with the data given in the relevant reference books regarding the change in the radiation characteristics of nuclear fuel during its operation in the VVER-1000. The results of comparison of the radiation characteristics of VVER-1000 fuel assemblies with the same burnup, but with different fuel loading schedules in the last year of operation are presented for a four-year fuel campaign. A significant influence on the radiation characteristics (radioactivity and residual energy release) of the fuel assembly load mode has been demonstrated. The simulation results show that the specific radioactivity and, accordingly, the total radioactivity of nuclear fuel in the VVER-1000 cores at the Zaporizhzhia NPP after ~1 year of forced outage decreased by ~100 times. Therefore, the possible radiation consequences in case of damage of nuclear fuel located in the core or unloaded into the spent fuel pools will be much lower than in the case of an accident at an operating reactor. The same applies to comparisons of the consequences of a possible accident at the ZNPP with the consequences of the accident at the Chornobyl NPP in 1986, which occurred at a working reactor with the release of at least ~3–5 % of nuclear fuel.

A novel resonant controller for sea-induced rotor blade vibratory loads reduction on floating offshore wind turbines

A novel multi-layer control approach for offshore floating wind turbines is presented, suitable for alleviating the vibratory loads while keeping the generator power output stable. It consists of the simultaneous application of different control strategies, each optimized for a specific objective. The proposed multi-layer scheme’s main scope is to reduce the Levelized Cost of Energy. Two resonant controllers based on collective blade pitch actuation are applied for the rejection of the vibratory loads induced by sea waves. In contrast, a proportional–integral controller, fed by measured cyclic blade root flapping moments, provides the blade cyclic pitch to be actuated to reduce blade root loads at the rotor revolution frequency. The proposed control strategy is validated by simulations on: (i) the NREL (U.S. National Renewable Energy Laboratory) 5 MW wind turbine, supported by a spar buoy or a semi-submersible platform; (ii) the 15 MW IEA (International Energy Agency) wind turbine supported by a semi-submersible platform. These show that significant reductions of the vibratory blade root flapping moments and rotor nacelle assembly loads are achievable, thus demonstrating the good potential performance of the controller introduced.

Performance Analysis of Full Assembly Glass Fiber-Reinforced Polymer Composite Cross-Arm in Transmission Tower.

The usage of glass fiber reinforced polymer (GFRP) composite cross-arms in transmission towers is relatively new compared to wood timber cross-arms. In this case, many research works conducted experiments on composite cross-arms, either in coupon or full-scale size. However, none performed finite element (FE) analyses on full-scale composite cross-arms under actual working load and broken wire conditions. Thus, this work evaluates the performance of glass fiber reinforced polymer (GFRP) composite cross-arm tubes in 275 kV transmission towers using FE analysis. In this study, the performance analysis was run mimicking actual normal and broken wire conditions with five and three times more than working loads (WL). The full-scale assembly load test experiment outcomes were used to validate the FE analysis. Furthermore, the mechanical properties values of the GFRP composite were incorporated in simulation analysis based on the previous experimental work on coupons samples of GFRP tubes. Additionally, parametric studies were performed to determine the ultimate applied load and factor of safety for both normal and broken wire loading conditions. This research discovered that the GFRP composite cross-arm could withstand the applied load of five times and three times working load (WL) for normal and broken wire conditions, respectively. In addition, the factor of safety of tubes was 1.08 and 1.1 for normal and broken wire conditions, respectively, which can be considered safe to use. Hence, the composite cross-arms can sustain load two times more than the design requirement, which is two times the working load for normal conditions. In future studies, it is recommended to analyze the fatigue properties of the composite due to wind loading, which may induce failure in long-term service.

High precision assembly test technology for space high reliability thermoelectric refrigeration system

Abstract Space Thermoelectric cooler is a key component of cryogenic equipment, which is used for high efficiency refrigeration of spacecraft in orbit. Its assembly state directly determines the refrigeration effect and service life. At the same time, it is characterized by high brittleness and low strength. In the assembly to low temperature equipment, thermoelectric cooler is required to be closely connected with internal and external components to achieve seamless connection and efficient heat transfer. At the same time, it is necessary to prevent the damage caused by large compressive stress caused by excessive assembly load, so as to meet the purpose of long life, high reliability and stable operation. The stiffness curve of thermoelectric refrigerator was obtained by measuring the component displacement when the pressure was applied under the simulated thermoelectric refrigerator assembly state, which was used as the guiding parameter to guide the thermoelectric refrigerator assembly. Meanwhile, the damage of thermoelectric refrigerator under different pressure loads was checked. Explore the variation law of displacement under different preload of refrigeration components. Finally, the high precision assembly is realized by unified combination of thermoelectric refrigerator and structural components of refrigeration assembly to meet the requirements of high efficiency, high reliability and long life refrigeration of space cryogenic equipment.

Dynamic analysis and vibration reduction of mechanical-hydraulic coupled tunnel boring machine (TBM) main drive system

Tunnel Boring Machine always works in the changeable geologies with multiple drivers, which leads to severe vibration of the TBM main drive system and key component failures. The vibration characteristics of TBM under different working conditions and the vibration reduction analysis have important meanings. First of all, by considering the time-varying random loads of the cutters, the contact force of the gears, the stiffness of the main bearing, and the stiffness of the cylinders, a mechanical-hydraulic coupling nonlinear dynamic model of the TBM main drive system was built according to the assembly relationship and load transmission path of the main drive system. Secondly, the dynamic model of the TBM main drive system is verified by comparing the theoretical vibration with the real vibration of the TBM main drive system. The error of the vibration acceleration is 10% to 30%. Three typical loads are defined under typical working conditions, and the vibrations of the TBM main drive system under three typical loads were analyzed. Finally, the sensitivity analysis of the cylinder damping shows that the damping at the position of the propulsion cylinder has a great influence on the vibration of the TBM main drive system. The results show that when the damping coefficient is 2.5 × 106 N·s/m, the maximum reduction of axial acceleration of cutterhead is 0.64 g, and that of the main beam front section is 0.55 g. The variable damping coefficient vibration reduction strategies under three typical loads are verified.

Slinging Unit For A Hollow-Core Floor Slab Of Stand-Off Formwork

Due to the fact that hollow-core slabs without formwork are produced without slinging loops (features of manufacturing technology), the issue of installation and transportation of these slabs has been solved. A constructive and technological solution is proposed for a slinging unit, arranged in the body of the slab, without the use of a slinging loop, and having only an anchor rod-dowel through which it is possible to directly sling the slab without using traditional slinging loops. The unit is designed with a reduced metal consumption and does not change the technology for manufacturing hollow-core slabs without formwork. Found and summed up a theoretical basis for calculating the bearing capacity of the proposed slinging unit, arranged in a hollow-core slab without formwork. It was revealed that the bearing capacity of the proposed slinging assembly, arranged in the body of a hollow-core slab, under the action of assembly loads, depends on the force of splitting the concrete of the protective layer located above the anchor rod-dowel of this assembly (all other things being equal). The theoretical data of the study were verified by full-scale tests of plates with slinging units arranged in their body, carried out in accordance with the proposed constructive and technological development. A utility model patent was obtained for the development of a loopless slinging unit for a hollow-core slab without formwork.

Experimental Investigation of a Double-Acting Vane Pump with Integrated Electric Drive

The article presents an innovative design solution of a balanced vane pump integrated with an electric motor that has been developed by the authors. The designed and constructed bench, which enables testing of the system: power supply, converter, ntegrated motor—pump assembly and hydraulic load at different motor speeds and different pressures in the hydraulic system, is described. The electromagnetic and hydraulic processes in the motor-pump unit are investigated, and new, previously unpublished, results of experimental studies at steady and dynamic states are presented. The results of the study showed good dynamics of the integrated motor-pump assembly and proved its suitability to control the pump flow rate, and thus, the speed of the hydraulic cylinder or the speed of the hydraulic motor.

Robust, fractal theory, and FEM-based temperature field analysis for machine tool spindle

The friction heat of spindle bearing has a significant impact on the precision and dynamic performance of spindle unit, which is the main factor restricting the machining precision and efficiency of the machine tool (MT). In this research, fractal theory, which characterizes rough surface by fractal dimension and surface characteristic parameters, hybrid genetic algorithm is used to study the temperature field of a FANUC machining center spindle. The thermal contact resistance (TCR) of each contact surface is computed according to the geometric characteristics and assembly load characteristics of each contact surface of the spindle. Adopting central composite design experiment and finite element method, an in-deep analysis of the thermal characteristics of machine tool in different thermal boundary conditions was conducted and the influence of thermal contact resistances and instability of thermal boundary conditions on the temperature field analysis of machine tool was discussed. Through the temperature rise experiment on the machine tool, the results of simulation analysis and experiment show that the method introduced in this research to calculate the temperature field of machine tool is effective. The work introduced in this research is helpful for the thermal analysis of spindle in machine tool, which can be seen as a guide on spindle’s design and performance optimization.

Experimental updating of a segmented wind turbine blade numerical model using the substructure method

During the development of the wind turbine system, blades are considered as the most critical components. The blades’ dynamic characteristics must be investigated during the design process to improve their mechanical performance. This work presents an experimental updating of a segmented wind turbine blade numerical model. For this purpose, the blade segments were manufactured using the fused deposition 3D printing technology and assembled using a threaded spar and nut. For different values of the segments assembly load, the natural frequencies and damping ratios were identified using the eigensystem realization algorithm method. The dynamic behavior of the segmented blade was examined numerically using the three-node shell element, taking into consideration the additional stiffness generated by the applied assembly load. In this study, numerical and experimental modal analysis were used to identify the first five eigenfrequencies of the blade. To update the numerical model parameters, through the identified experimental results, an iterative method was developed based on the Craig–Bampton substructure approach. Results show that the blade natural frequencies are proportional to the segments assembly load. The application of the proposed method on the segmented blade numerical model updating shows that the present method is computationally efficient.

Modelling changes in modular taper micromechanics due to surgeon assembly technique in total hip arthroplasty.

The aim of this study was to develop a novel computational model for estimating head/stem taper mechanics during different simulated assembly conditions. Finite element models of generic cobalt-chromium (CoCr) heads on a titanium stem taper were developed and driven using dynamic assembly loads collected from clinicians. To verify contact mechanics at the taper interface, comparisons of deformed microgroove characteristics (height and width of microgrooves) were made between model estimates with those measured from five retrieved implants. Additionally, these models were used to assess the role of assembly technique-one-hit versus three-hits-on the taper interlock mechanical behaviour. The model compared well to deformed microgrooves from the retrieved implants, predicting changes in microgroove height (mean 1.1 μm (0.2 to 1.3)) and width (mean 7.5 μm (1.0 to 18.5)) within the range of measured changes in height (mean 1.4 μm (0.4 to 2.3); p = 0.109) and width (mean 12.0 μm (1.5 to 25.4); p = 0.470). Consistent with benchtop studies, our model found that increasing assembly load magnitude led to increased taper engagement, contact pressure, and permanent deformation of the stem taper microgrooves. Interestingly, our model found assemblies using three hits at low loads (4 kN) led to decreased taper engagement, contact pressures and microgroove deformations throughout the stem taper compared with tapers assembled with one hit at the same magnitude. These findings suggest additional assembly hits at low loads lead to inferior taper interlock strength compared with one firm hit, which may be influenced by loading rate or material strain hardening. These unique models can estimate microgroove deformations representative of real contact mechanics seen on retrievals, which will enable us to better understand how both surgeon assembly techniques and implant design affect taper interlock strength. Cite this article: Bone Joint J 2020;102-B(7 Supple B):33-40.

Probabilistic fatigue assessment of monitored railroad bridge components using long-term response data in a reliability framework

Fatigue is a primary concern for railroad bridge owners because railroad bridges typically have high live load to dead load ratios and high stress cycle frequencies. However, existing inspection and post-inspection analysis methods are unable to accurately consider the full influence of bridge behavior on the fatigue life of bridge components. Reliability-based fatigue analysis methods have emerged to account for uncertainties in analysis parameters such as environmental and mechanical properties. While existing literature proposes probabilistic fatigue assessment of bridge components, this body of work relies on train parameter estimates, finite element model simulations, or controlled loading tests to augment monitoring data. This article presents a probabilistic fatigue assessment of monitored railroad bridge components using only continuous, long-term response data in a purely data-driven reliability framework that is compatible with existing inspection methods. As an illustrative example, this work quantifies the safety profile of a fracture-critical assembly comprising of six parallel eyebars on the Harahan Bridge (Memphis, TN). The monitored eyebars are susceptible to accelerated fatigue damage because changes in the boundary conditions cause some eyebars to carry a greater proportion of the total assembly load than assumed during design and analysis; existing manual inspection practices aim to maintain an equal loading distribution across the eyebars. Consequently, the limit state function derived in this article accounts for the coupled behavior between fatigue and relative tautness of the parallel eyebars. The reliability index values for both the element (i.e. individual eyebars) and system (i.e. full eyebar assembly) reliability problems are assessed and indicate that under the conservative assumption that progressive failure is brittle, first failure within the parallel eyebar system is generally equivalent to system failure. The proposed method also serves as an intervention strategy that can quantify the influence of eyebar realignment on the future evolution of the reliability index.

Influence of Different Damage Patterns of the Stem Taper on Fixation and Fracture Strength of Ceramic Ball Heads for Total Hip Replacement.

Background Modularity finds frequent application in total hip replacement, allowing a preferable individual configuration and a simplified revision by retaining the femoral stem and replacing the prosthetic head. However, micromotions within the interface between the head and the stem taper can arise, resulting in the release of wear debris and corrosion products. The aim of our experimental study was to evaluate the influence of different taper damages on the fixation and fracture stability of ceramic femoral heads, after static and dynamic implant loading. Methods Ceramic ball heads (36 mm diameter) and 12/14 stem tapers made of titanium with various mild damage patterns (intact, scratched, and truncated) were tested. The heads were assembled on the taper with a quasistatic load of 2 kN and separated into a static and a dynamic group afterwards. The dynamic group (n = 18) was loaded over 1.5 million gait cycles in a hip wear simulator (ISO 14242-1). In contrast, the static group (n = 18) was not mechanically loaded after assembly. To determine the taper stability, all heads of the dynamic and static groups were either pulled off (ASTM 2009) or turned off (ISO 7206-16). A head fracture test (ISO 7206-10) was also performed. Subsequent to the fixation stability tests, the taper surface was visually evaluated in terms of any signs of wear or corrosion after the dynamic loading. Results In 10 of the 18 cases, discoloration of the taper was determined after the dynamic loading and subsequent cleaning, indicating the first signs of corrosion. Pull-off forces as well as turn-off moments were increased between 23% and 54% after the dynamic loading compared to the unloaded tapers. No significant influence of taper damage was determined in terms of taper fixation strength. However, the taper damage led to a decrease in fracture strength by approximately 20% (scratched) and 40% (truncated), respectively. Conclusion The results suggest that careful handling and accurate manufacturing of the stem taper are crucial for the ceramic head fracture strength, even though a mild damage showed no significant influence on taper stability. Moreover, our data indicate that a further seating of the prosthetic head may occur during daily activities, when the resulting hip force increases the assembly load.