Article
Engineering, Mechanical
M. S. Wang, X. D. Jia, W. Y. Lv, W. H. Sun, F. X. Bai, H. Guo
Summary: The main reason for the failure of screw compressor shaft is multisource fatigue due to lack of surface quenching, and better control of surface quenching is strongly recommended to prevent similar failures.
ENGINEERING FAILURE ANALYSIS
(2021)
Article
Engineering, Mechanical
Mohammed S. Matar, Sami E. Alkhatib
Summary: This study presents a comprehensive failure analysis of a stepped shaft in a rubber recycling factory. The investigation aims to identify the underlying cause of the shaft's failure and provide insights for enhancing machinery reliability. The study reveals low-cycle fatigue primarily caused by small surface imperfections, with stress concentration at the diameter change. Misalignment of the shaft contributes to excessive vibration and failure. Implementing corrective measures, such as correct alignment, reinforced fixation, and construction of a steel-reinforced concrete base, successfully prevents shaft failures.
ENGINEERING FAILURE ANALYSIS
(2023)
Article
Materials Science, Multidisciplinary
Rodrigo S. Miranda, Clarissa Cruz, Noe Cheung, Adilto P. A. Cunha
Summary: The study focused on the failure of a shaft in a speed reduction box in the mining industry. Analysis revealed that the shaft material was inadequately heat treated, with large amounts of inclusions and concentrated pores, leading to decreased fatigue resistance and life of the material.
Article
Engineering, Mechanical
Mengda Hua, Chi Cao, Youquan Cai, Jie Ge, Fengping Zhong, Jianfeng Mao
Summary: This study analyzes and improves the failure of the pump shaft in a multistage centrifugal pump. Through microscopic observation and analysis of the fractured pump shaft, it is found that the failure is caused by fatigue fracture with multi-source crack initiation. Numerical analysis shows that there is stress concentration at the fracture, exceeding the fatigue limit of the material. By designing appropriate fillet radius and elastic coupling, the stress concentration can be reduced and the service life of the pump shaft can be improved. The improved pump shaft's fatigue life is verified through experiments.
ENGINEERING FAILURE ANALYSIS
(2023)
Article
Engineering, Mechanical
Sai Cai, Jinquan Sun, Qingkun He, Tong Shi, Dongrui Wang, Jinwei Si, Jie Yang, Fujie Li, Kun Xie, Min Li
Summary: This study analyzed the fatigue performance of the 16MnCr5 steel gear shaft in truck steering, finding that cracks mainly appeared at the fillet of the top, pitch circle, and root of the gear. The size and distribution of slag inclusions also affected the occurrence of cracks.
ENGINEERING FAILURE ANALYSIS
(2021)
Article
Engineering, Mechanical
Xiao-lei Xu, Zhi-wei Yu
Summary: The fracture of the bulk-ship's intermediate shaft was mainly due to multiple origins fatigue fracture caused by inadequate material strength due to low carbon content, high stress concentration caused by geometric design, and stress concentration increased by circumferential machining grooves. Through static strength analysis, it was found that the design of the intermediate shaft had issues, with the safety factor lower than the standard requirement.
ENGINEERING FAILURE ANALYSIS
(2021)
Article
Engineering, Mechanical
Vidar Hellum, Tom Lassen, Andrea Spagnoli
Summary: The premature fatigue failure of a large intermediate propeller shaft in a shuttle tanker is discussed and analyzed, focusing on the crack growth phase with short fatigue life. Crack growth modelling based on engineering fracture mechanics is used for life predictions, with enhanced geometry functions proposed to reconstruct the observed crack path and shape development. Various loading modes and multi-axial stress states are applied to pursue the observed crack behavior.
ENGINEERING FAILURE ANALYSIS
(2021)
Article
Mechanics
Shu Zhang, Rui Ma, Yu Hu, Qingbin Li
Summary: The fatigue failure problem can be explained by fatigue stress-strain envelope, and using fatigue stress-strain for evaluation can eliminate the uncertainty in selecting fatigue criteria in engineering applications. However, the use of experimental fatigue envelope criterion based on stress-strain curve is limited to concrete and rocks, and it cannot predict the fatigue failure time. To improve the availability of fatigue stress-strain envelope criterion, a fatigue failure criterion is proposed based on the static constitutive curve as the limit value, which describes high-cycle and low-cycle fatigue failure through theoretical deduction and analysis of experimental results. The proposed criterion reveals the mechanism that fatigue life is dominated by fatigue failure stress-strain in the fatigue envelope surface. The comparison between calculated and experimental fatigue life shows that the proposed criterion effectively describes fatigue failure and has comprehensive application prospects.
ENGINEERING FRACTURE MECHANICS
(2023)
Article
Multidisciplinary Sciences
Haiqin Song, Jinfeng Zhang, Fan Zhang
Summary: This study analyzed the hydraulic performance and rotor strength and critical speed of a vertical long shaft fire pump through experiments and numerical simulations. The results indicated that the selected model met the safety and dynamic design requirements, providing theoretical support for the structural design optimization of vertical long shaft fire pumps.
SCIENTIFIC REPORTS
(2022)
Article
Engineering, Mechanical
Junwen Lu, Hao Zheng, Muhammad Husnain Haider, Yanpeng Feng, Pengpeng Zhi, Jian Cheng, Zhonglai Wang
Summary: This study systematically investigates the root causes and failure mechanisms of flywheel hub fatigue failure in a heavy-fuel piston engine through a comprehensive approach combining macroscopic fracture analysis, microstructural evaluation, chemical composition analysis, and FEA simulation. The failure mode of the flywheel hub is fatigue caused by cyclic loading, and the mechanism behind the failure is facilitated by severe cyclical loads and design flaws resulting in a high concentration of stress between the spokes due to rounding. Finite element analysis simulations are conducted to validate the fatigue mechanism, and precautionary measures such as regular non-destructive testing, geometry redesign, and moderate operation of the power lever are proposed.
ENGINEERING FAILURE ANALYSIS
(2023)
Article
Engineering, Mechanical
Basavaraj Padasale, Gurunath S. Kulkarni, J. K. Rakshan Kumar, Sumanth Govindaran, Subray R. Hegde
Summary: This study investigates the failure of a fire water jockey pump shaft in a petrochemical plant's fire-station. Through various analysis methods, it is concluded that the primary cause of failure is the use of a square-ended key in a round-ended keyway, as well as the use of different materials for the shaft and the key. To prevent similar failures in the future, it is recommended to improve the key design and use the same grade of steel for both the shaft and the key.
ENGINEERING FAILURE ANALYSIS
(2022)
Article
Thermodynamics
Hao Guo, Haitao Duan, Jianzhong Lei, Dongfeng Wang, Sanming Du, Yongzhen Zhang, Zongye Ding
Summary: This study conducted a failure analysis on the engine water pump shaft bearing using various methods, clarified the wear behavior and failure mechanisms, and proposed preventive measures. The failure of the bearing was reflected in the fracture of the bearing cage and serious wear of the roller and mandrel.
ADVANCES IN MECHANICAL ENGINEERING
(2021)
Article
Engineering, Mechanical
Haibo Yang, Ping Wang, Hongliang Qian, Pingsha Dong
Summary: This study investigates the fatigue test conditions for reproducing weld toe cracking into U-rib wall in orthotropic bridge decks using both experimental and numerical methods. The traction structural stress method is proven effective in evaluating this fatigue failure mode (referred to as toe-U rib) and its associated test conditions. Experimental validations consistently observed the toe-U rib failure mode, and it was found that variations in weld penetration do not impact the failure mode and its fatigue capability.
INTERNATIONAL JOURNAL OF FATIGUE
(2022)
Article
Engineering, Mechanical
Yu Hu, Ding Zhang, Linzhi Xu, Tianyang Sun, Peng Zhang, Jichao Lei
Summary: Flange joint on a marine shaft is more susceptible to fatigue fracture due to stress concentration effect, and the torsional fatigue performance near the joint should be given more attention for safe navigation of ships. Fatigue analysis of 34CrNi3Mo steel with a stress concentration factor of 1.45 was conducted using simplified 34CrNi3Mo specimens with u-notch subjected to torsional fatigue loading. The S-N curve and fatigue life of the alloy steel were numerically calculated and compared with experimental results, and the effect of different v-notch angles on fatigue performance was also examined.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Article
Engineering, Mechanical
Hu Yongxu, Andy Chit Tan, Chen Liang, Yanping Li
Summary: The investigation revealed that the fracture of high-speed train motor connecting bolts was caused by alternating load due to misaligned cardan shaft. Further analysis showed that the material at the bottom surface of the bolts reached the fatigue limit. To prevent similar accidents, an innovative strategy was proposed.
ENGINEERING FAILURE ANALYSIS
(2021)
Article
Engineering, Mechanical
Pedro R. da Costa, Luis Reis, Manuel Freitas
Summary: Ultrasonic fatigue testing is a method that uses resonance to achieve very high cyclic load frequencies for studying high cycle fatigue. This study modified the geometry of the specimen and conducted numerical and experimental modal behavior analysis to achieve reliable multiaxial fatigue testing. The results prove a clear trend in crack propagation details with the increase of the induced stress ratio.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2023)
Article
Materials Science, Multidisciplinary
Diogo Pereira, Frederico P. D. Alves, Luis Reis, Marco Leite, Augusto M. Deus, Manuel Sardinha, M. Fatima Vaz
Summary: Sandwich panels, consisting of a core and two layers, have a wide range of applications and their mechanical properties are influenced by the geometry of the core. This study investigates the performance of body- and face-centred parallelepiped with struts in z-axis structure by changing its dimensions and relative density, and the results show that the dimensions of the struts and the relative density affect the mechanical performance and failure modes of the panels.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART L-JOURNAL OF MATERIALS-DESIGN AND APPLICATIONS
(2023)
Review
Engineering, Manufacturing
Carlos M. S. Vicente, Manuel Sardinha, Luis Reis, Antonio Ribeiro, Marco Leite
Summary: This research provides a review of large-format AM processes for polymers and market research on large-format polymer commercial printers. The advancements in LFAM systems configurations and their control aspects are discussed. The material extrusion AM process family is found to be the most suitable for producing large parts.
PROGRESS IN ADDITIVE MANUFACTURING
(2023)
Article
Energy & Fuels
Mario Vieira, Brian Snyder, Elsa Henriques, Craig White, Luis Reis
Summary: Offshore wind energy is a promising renewable source that can contribute to energy independence, but it requires cost reduction strategies for future development. This study evaluates the viability of structural health monitoring (SHM) systems on the support structures of bottom-fixed offshore wind (BFOSW) and their impact on the farm's life-cycle. Results show that implementing SHM systems can shift maintenance strategies and extend the operational life of the farm.
Review
Materials Science, Multidisciplinary
Manuel Sardinha, M. Fatima Vaz, Tania R. P. Ramos, Luis Reis
Summary: The interest in airless or non-pneumatic tire (NPT) structures emerges due to potential performance and environmental advantages. However, large-scale production of NPTs for most applications is not yet established. This study provides an in-depth review of the mechanical design and development of NPTs, discusses key research areas, and highlights the need for further investigation in the production, performance, and reliability of NPTs.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART L-JOURNAL OF MATERIALS-DESIGN AND APPLICATIONS
(2023)
Article
Materials Science, Multidisciplinary
Felipe Klein Fiorentin, Luis Reis, Grzegorz Lesiuk, Ana Reis, Abilio de Jesus
Summary: A trend of increasing excitation frequencies in fatigue testing has been observed due to advances in control and excitation systems. While high testing frequencies save time and money, they also pose challenges for measurement systems and temperature control. Being able to predict and control sample temperature is essential in high frequency fatigue testing.
Article
Crystallography
Vitor Anes, Rogerio Moreira, Luis Reis, Manuel Freitas
Summary: Under strain control tests and cyclic loading, extruded magnesium alloys exhibit a special mechanism of plastic deformation called twinning and de-twining. This behavior cannot be fully characterized with traditional numerical tools used for steels or aluminum alloys. To address this, a new phenomenological model called hypo-strain has been developed to accurately predict the cyclic stress-strain evolution of magnesium alloys. This study aims to describe the local cyclic elastic-plastic behavior of AZ31B-F magnesium alloy under multiaxial cyclic loading using Abaqus incremental plasticity with the implementation of the hypo-strain model in the UMAT subroutine of Abaqus/Standard.
Article
Engineering, Mechanical
Alexandra A. Arbex, Luis Reis, Gisele F. C. Almeida, Abrao C. Merij, Marcos Massi, Antonio A. Couto
Summary: This study aimed to investigate the influence of coating a thin film of Silicon Carbide and chromium interlayer on the fatigue behavior and failure evaluation of Ti-6Al-4V alloy. The characterization of the layer included roughness, thickness, and adhesion measurements. Uni-axial fatigue tests were conducted under R = 0.1, and SEM was used to observe and identify the fracture surfaces and failure mechanisms. Coated specimens using the DC source exhibited an increased number of cycles to failure, with crack initiation occurring internally rather than superficially. The layer remained adhered to the specimens even after the tests, indicating its effectiveness. In contrast, specimens coated using the HiPIMS source showed a decreased number of cycles to failure, predominantly superficial cracks, and reduced adhesion of the deposited film, proving to be ineffective and worsening the material's fatigue behavior.
ENGINEERING FAILURE ANALYSIS
(2023)
Article
Materials Science, Multidisciplinary
M. C. Salama, F. Alves, L. Reis, A. M. Deus, M. B. Silva, C. Santos, M. J. Carmezim, M. F. Vaz
Summary: Biodegradable metals, particularly iron, have potential as temporary bone implants, but have drawbacks such as high stiffness and low degradation rate. The use of porous materials can overcome these disadvantages by decreasing strength and increasing degradation rate. This study aimed to develop iron porous structures with adequate mechanical and corrosion performance. Three types of structures were studied, and results showed that both mechanical and corrosion properties depended on relative density and pore arrangement. Structures with low relative density exhibited similar compressive strength to human trabecular bone and degradation rates suitable for bone substitutes.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART L-JOURNAL OF MATERIALS-DESIGN AND APPLICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Vitor Anes, Cristina B. Neves, Valeria Bostan, Sergio B. Goncalves, Luis Reis
Summary: The aim of this study was to evaluate the retention forces of digitally fabricated removable partial denture clasps over time. The teeth were digitized using a laboratory scanner and two types of clasps were designed and fabricated using a direct laser sintering process. A total of 20,000 cycles of clasp insertion and removal were performed, and the retention forces were recorded. Statistical analysis showed that there were no significant differences in the retention forces between the two types of clasps in most cycles.
APPLIED SCIENCES-BASEL
(2023)
Article
Crystallography
Fernando Almeida Costa Oliveira, Manuel Sardinha, Jose Galindo, Jose Rodriguez, Inmaculada Canadas, Marco Leite, Jorge Cruz Fernandes
Summary: This study presents a novel approach for manufacturing porous materials as solar receivers for concentrated sun radiation. By using 3D-printing technology, the materials showed good thermal performance and high solar absorptance after thermal cycling.
Article
Engineering, Mechanical
Willy Ank de Morais, Railson Bolsoni Falcao, Mario Boccalini Jr, Fernando Jose Gomes Landgraf
Summary: This study compares the fatigue behavior of bcc Nb-48 wt%Ti (Ti-36at%Nb) alloy parts processed by Laser Powder Bed Fusion (L-PBF) using two different types of powders (spherical powder produced by Plasma Atomization and irregularly shaped powder produced by Hydride-Dehydride). The results show that the fatigue behavior is similar for both powders, but the specimens produced from the Hydride-Dehydride powder have higher dispersed results. Fracture primarily occurs in the porosities near the machined sample surface, and the fatigue cracks propagate in a zigzag mode parallel to the L-PBF building direction.
ENGINEERING FAILURE ANALYSIS
(2024)
Article
Engineering, Mechanical
Guoxi Jing, Shuai Sun, Teng Ma, Shubo Li, Tian Ma, Junchao Wei, Jianchao Pang
Summary: This study proposes a parameter identification method for predicting the TMF life of CGI materials used in cylinder heads. The study evaluates the TMF behavior of RuT450 material and successfully predicts its TMF life using multi-objective optimization. The results highlight the influence of plastic strain amplitude, temperature, and strain rate on the damage mechanism and life prediction.
ENGINEERING FAILURE ANALYSIS
(2024)
Article
Engineering, Mechanical
Xin Zhang, Xu Li, Weipeng Xu, Kuidong Gao, Kao Jiang, Xinyu Wang, Hongxin Wei
Summary: Conical picks are commonly used in tunnel excavation and often experience high temperatures during the cutting process. This study investigated the influence of temperature on the wear of conical picks and proposed a method for measuring rock abrasiveness that takes into account the thermal effect. The experimental results showed that cooling liquid reduced the maximum temperature and the mean mass loss of the conical pick. Additionally, the study examined the characteristics of oxygen and found evidence of peeling, cracking, and oxidation on the grinding rod used for rock abrasiveness measurement.
ENGINEERING FAILURE ANALYSIS
(2024)
Article
Engineering, Mechanical
Vivek Srivastava, Deependra Singh, A. G. Rao, V. P. Deshmukh
Summary: Engine gear failures are a significant concern in various industries. Investigating each gear failure and determining the root cause is important for preventing future failures. This study used experimental and numerical analysis techniques to investigate the premature failure of a flywheel gear in a marine diesel engine. The findings revealed that the gear failed due to overload stresses caused by overload torque generated from sudden inertial thrust in the internal combustionengine.
ENGINEERING FAILURE ANALYSIS
(2024)
Article
Engineering, Mechanical
Jun Zhang, Weidong Liu, Feilong Liu, Zhiqiang Yang, Jinfang Peng, Minhao Zhu
Summary: During a major overhaul of an aeroengine, a cracked stator vane of the low-pressure compressor was discovered, with the crack originating from a corrosion pit located on the arc transition between the leading edge and the upper edge plate. The fracture surface exhibited signs of fatigue cracks, indicating a pit-related fatigue crack. Metallographic examination revealed that most corrosion pits were distributed beneath the bulging or peeling paint layer on the leading edge and the concave side. Identification of the corrosion products showed the presence of sulfate and alumina, suggesting atmospheric corrosion as a likely cause for the cracked stator vane.
ENGINEERING FAILURE ANALYSIS
(2024)
Article
Engineering, Mechanical
Juan Jose Jimenez de Cisneros Fonfria, Ester Olmeda, Susana Sanz, Maria Garrosa, Vicente Diaz
Summary: Energy absorbing devices in vehicles can partially transform impact energy and protect passengers. In this paper, the failure analysis of the underframe crumple zone in a train car was conducted through finite element simulations, showing that the component acted properly after the impact.
ENGINEERING FAILURE ANALYSIS
(2024)
Article
Engineering, Mechanical
Fengqi Zhang, Gang Luo, Haiyang Zhang, Peihong Cong, Lulu Liu, Wei Chen
Summary: In this study, a predictive model for bird strike trajectory was developed based on the quasi-linear viscoelastic model. By combining simulation analysis under multiple conditions, the model reproduced the trajectory change law in low and medium speed bird impact experiments.
ENGINEERING FAILURE ANALYSIS
(2024)
Article
Engineering, Mechanical
S. M. de Gouveia, L. de Abreu Correa, D. B. Teles, M. Oliveira, T. G. R. Clarke
Summary: Emergency Shutdown Valves (EDSVs) are used in industrial applications to interrupt fluid flow during hazardous events. The damage to the valve seats can be detected by analyzing the pressure and torque data. This study compared three processing options and found that evaluating the complete signature with a Gradient Boosting Classifier algorithm is the most effective strategy.
ENGINEERING FAILURE ANALYSIS
(2024)
Article
Engineering, Mechanical
Xinyan Jin, Kai Wang, Hongwei Qian
Summary: This study investigated the root cause of an abnormal premature groove-clogging failure on a sink roll in a hot-dip galvanizing line. It was found that the failure was caused by the buildup of a large amount of Fe2Al5Znx dross in the grooves, and the key factor was the control of Tstrip.
ENGINEERING FAILURE ANALYSIS
(2024)
Article
Engineering, Mechanical
Zhiqiang Li, Jie Li, Cen Li, Xiaodong Xie, Zhiyong Yang
Summary: In this study, the microstructure evolution of the material in the hot spot area of the high-speed train brake disc was observed and the mechanism of mechanical property degradation was obtained through tensile tests. The research results provide guidance for crack damage identification of the brake disc and condition-based maintenance.
ENGINEERING FAILURE ANALYSIS
(2024)
Article
Engineering, Mechanical
Lijia Luo, Yincheng Wang, Wei Chen, Zuming Zhao, Wenfei Chen, Shiyi Bao
Summary: Tube-to-tube impact wear is a significant factor in the failure of alloy 690 tubes in nuclear steam generators. This paper investigates the wear damage mechanism and detection method of alloy 690 tubes under tube-to-tube impact loads. The results reveal the wear damage mechanism through analysis of macro and micro morphologies as well as metallographic structures. A nonlinear ultrasonic wave mixing method is proposed for damage detection and a detection device is developed to implement this method. Experimental results indicate that the damage mode of tube-to-tube impact wear varies with impact load and cycle number, and the nonlinear modulation index is effective in assessing the damage degree of alloy 690 tubes.
ENGINEERING FAILURE ANALYSIS
(2024)
Article
Engineering, Mechanical
Xing-Ju Yang, Feng Lin, Xu Du, Lu Qiu
Summary: This paper proposes a novel method of improving the progressive collapse resistance of RC frame structures by adding locally debonded kinked steel plates (KPs). Experimental tests and finite element analysis reveal that the addition of KPs significantly enhances the ultimate resistance and deformability of the beam-slab substructures. The mechanism of resistance improvement is explained, and an analytical model is developed for predicting the ultimate resistance of the structures.
ENGINEERING FAILURE ANALYSIS
(2024)
Article
Engineering, Mechanical
Xiaohe Wang, Zengqiang Cao
Summary: This paper presents a dynamic installation (DI) method based on electromagnetic force to reduce damage to composite laminates and improve joint performance. The study shows that DI can effectively decrease installation resistance, reduce severe damage to laminates, and improve stress distribution in the joint.
ENGINEERING FAILURE ANALYSIS
(2024)
Article
Engineering, Mechanical
Jitong Cui, Yingying Kong, Cuiwei Liu, Baoping Cai, Faisal Khan, Yuxing Li
Summary: This paper presents a method for quantifying the failure probability of hydrogen doped pipelines and utilizes Bayesian network for quantitative calculation. The results show that this method can more accurately assess the failure probability of hydrogen doped pipelines and provide a decision basis for preventing failure accidents.
ENGINEERING FAILURE ANALYSIS
(2024)
Article
Engineering, Mechanical
Yiping Jiang, Maoru Chi, Jungang Yang, Liangcheng Dai, Yuchen Xie, Zhaotuan Guo
Summary: This article investigates and simulates the derailment of empty freight trains at the switch section of a turnout in the diverging route, and proposes preventive measures. The results show that the derailment is caused by the combined effect of various factors, and reducing the longitudinal coupler force and the wheel rail friction coefficient can decrease the possibility of derailment. Additionally, installing a guard rail in front of the turnout can effectively prevent derailment.
ENGINEERING FAILURE ANALYSIS
(2024)
