Joint Material Research Articles

Determination of residual stresses in metallic materials based on spherical indentation strain

Abstract A spherical indentation strain method was proposed to determine surface residual stress in this study. Through numerical simulation, the effect of the material properties and residual stress on the plastic zone around the indentation was investigated, and the ideal strain measurement region appropriate for diverse materials was identified. Meanwhile, the presence of residual stress in material will cause the strain increment in the strain measurement area near the indentation to change. Based on the relationship among strain increment, residual stress and material mechanical properties, the calibration equation of residual stress for different materials were established. A portable residual stress loading device was developed and combined with the indentation test to calibrate the 316 L and 304 stainless steel of nuclear welding joint material. The reliability of this method was verified, and it provides convenience for the calibration of the residual stress of stainless steel materials.

The Effect of Heat Input on the Tensile Strength and Toughness of welded SS400 Materials by SMAW

Joint materials using welding require the correct stages, starting from the design stage to the processing stage. The design stage starts from the selection of the type of welding, to the selection of the seam angle used. Meanwhile, at the processing stage, the current strength will be selected according to the processing position. The purpose of this study was to determine the effect of welding heat input on the mechanical strength of SS-400 steel in SMAW welding. In this study the material used was SS-400 with current variations of 90 A and 100 A. The results showed that the welding current affected the tensile strength and toughness of the material. The welding current of 100 A has the highest tensile strength and toughness, and then 90 A which has the lowest tensile strength and toughness, while the strain that occurs at current 90A is 13.53%, and the strain that occurs at current 100 A is 12.07%.

Comparison of nano-silver solder joints and SAC305 based on ANSYS simulation and life prediction

With the rapid development of microelectronic interconnection technology, the reliability requirements of electronic products are becoming higher and higher. Among them, temperature has the greatest impact on electronic devices. Due to the different coefficients of thermal expansion (CTE) between the many materials of a chip, the inside of a solder joint is subjected to cyclic temperature action. Under the effect of cyclic temperature, the solder joints are subject to internal fracture resulting in the failure of the solder joint. Therefore, it is necessary to find a more reliable material for the solder joint. In this paper, the advantages and disadvantages of pure silver material and low silver material are compared by finite element simulation analysis of nano-silver pure silver material and SAC305 low silver material, and the fatigue life prediction of nano-silveris predicted by a life prediction model. Then, using the Electric Power Research Institute estimation method to estimate the fatigue life of solder joints, the results are compared with those calculated by the finite element method.

Flexural Behavior of Prefabricated RC Bridge Deck with Different Joint Materials

This study investigated the flexural behavior of prefabricated RC bridge decks with different joint materials, normal strength concrete or UHPC (normal strength concrete for RC deck, while UHPC means ultra-high performance concrete). A total of three specimens were tested and subjected to four-point bending loads. The load–deflection curve, strain curve, load–crack width curve, and failure mode were analyzed. Numerical models with cohesive models were built and verified with test results to explore the force-transferring mechanism. The results show that UHPC effectively improved the crack strength, flexural strength, and failure mode. Compared with the joint with normal-strength concrete, the crack strength and flexural strength increased by 66.7% and 6%, respectively. The failure mode of the specimen with UHPC as joint material changed from a concentrated cracking failure of the joint to a multi-crack development failure. The behavior of the specimen with UHPC as joint material was similar to the monolithically cast specimen. In addition, the application of the current design method was evaluated and compared with test results.

Decay of ignimbrite fairy chimneys of Arizona's Basin and Range Province, USA

AbstractFairy chimneys of ignimbrite are well studied in Cappadocia in central Anatolia, Turkey. The ignimbrite landforms of Arizona's Basin and Range, USA, in contrast, remain relatively unexplored in geomorphic scholarship, despite decades of geological research on the characteristics of the ignimbrites themselves. This research focuses on the rock‐decay processes that modify Arizona's Basin and Range fair chimneys. Dissolution of glass and groundmass, measured along joints using digital image processing of back‐scattered electron microscope imagery, reveal a 3× higher porosity than inside the rock interior. This method also measured a 3‐4× increase in dissolution near the base of the chimney compared with the rock interior, leading to notch development that promotes chimney mass wasting and subsequent ballistic impacts. Epilithic organisms studied with electron microscopy both enhance rock decay and promote case hardening. These observations are consistent with prior understanding of how fairy chimneys evolve over time: columnar joints exposed on cliff faces experience enough decay to allow erosion of joint material, this erosion separates the chimney from the rock face and notch development near the chimney base promotes mass wasting. The rock‐decay processes studied here likely operate on very different timescales. Mass wasting events leading to ballistic impacts occur at observable timescales. Varnish microlamination dating, using ultrathin sections of rock varnish formed on fairy chimneys, indicates that the case hardening of the top of fairy chimneys are much more stable than the sides; the tops last experienced surface detachment during the early Holocene, as opposed to the sides that experienced flaking throughout the late Holocene. The timescale of basal notch development is not known, with the exception that the very surface of notches erode at rates too fast to accumulate rock varnish. The timescales of epilithic organisms enhancing rock decay and dissolution of columnar joints are not known.

Post-Weld Heat Treatment of S690QL1 Steel Welded Joints: Influence on Microstructure, Mechanical Properties and Residual Stress

During the manufacturing of welded structures, some degree of residual stresses occurs. The classic approach to residual stress reduction is Post-Weld Heat Treatment (PWHT). In the case of structural grade mild steels, the thermal process is well established. In case of S690QL1 High Strength Steel (HSS), which is manufactured using the Quenching and Tempering (QT) process considered in this paper, only limited PWHT treatment is possible without deterioration of mechanical properties. Since this steel grade is susceptible to subsequent heat input, the challenge is to establish adequate PWHT parameters, achieving residual stress reduction while retaining sufficiently high mechanical properties. The paper considers X joint welded HSS steel plates with slightly overmatching filler metal. The welded coupon is prepared and subjected to PWHT treatment. The research on the influence of heat treatment was performed using the four different PWHT cycles and initial As-Welded (AW) material condition. The authors proposed those PWHT cycles based on available resources and the literature. Process holding temperature is considered the variable parameter directly related to the behaviors of material properties. The methodology of welded joint analysis includes experimental testing of mechanical properties, metallographic examination, and residual stress quantification. Testing of mechanical properties includes tensile testing, Charpy V-notch impact testing, and hardness testing in scope of complete welded joint (BM + HAZ + WM). Metallographic examination is performed in order to characterize the welded joint material in relation to applied PWHT cycles. In order to quantify residual stresses, all heat-treated samples were examined via the X-ray diffraction method. Mechanical properties testing determined that an increase in PWHT cycle holding temperature leads to degradation of tested mechanical properties. For specific zones of the welded joint, the decreasing trend from AW condition to Cycle D (max. 600 °C) can be quantified. Based on representative specimens comparison, strength values (BM ≤ 5.7%, WM ≤ 12.1%, HAZ ≤ 20%), impact testing absorbed energy (BM = 17.1%, WM = 25.8%, FL = 12.5%, HAZ = 0.6%), and hardness values (BM = 4.1%, WM = 3.2%, CGHAZ = 16.6%, HAZ = 24.2%) are all exhibiting decrease. Metallographic examination, using the light microscopy, after the exposure to PWHT thermal cycles, did not reveal significant changes in the material throughout all specific welded joint segments. Average relative reduction in residual stress in correlation with PWHT temperature can be observed (AW = 0%, Cycle A (max. 400 °C) = 72%, Cycle B (max. 530 °C) = 81%, Cycle C (max. 550 °C) = 93% and Cycle D (max. 600 °C) = 100% stress reduction). It can be concluded that S690QL1 HSS welded joints can generally be subjected to PWHT, while adhering to the limits of the material and process. In the authors’ shared opinion, it is advisable to use the PWHT Cycle C (max. 550 °C) with 93% RS reduction, while mechanical properties retain high values.

Experimental Study on the Wear Characteristics of Textured Joint Surfaces under Bionic Lubrication

Ti15Mo7Zr15Ta1.00Si titanium alloy contained higher concentration of silicon and better elastic properties, excellent biocompatibility and lower processing cost. To investigate the influence of texture shapes and parameters of joint surfaces on the friction and wear properties under bionic lubrication conditions, three types of texture morphologies (circular, elliptical, and equal-width grating) with the same pit depth and surface coating rate were processed on a Ti15Mo7Zr15Ta1.00Si titanium alloy using a picosecond laser processing system in this study. Then, the "ceramic–metal" friction and wear tests of textured and smooth samples under lubrication with bovine serum protein were performed using a UMT-3 multifunctional friction and wear testing machine. The results showed that the surface micro-texture morphology could improve the anti-friction properties of titanium alloy artificial joint materials. The wear resistance of the circular micro-dimples improved with an increase in the circular diameter. In the elliptical micro-dimple texture morphology, the vertical arrangement of the ellipses could provide the maximum bearing capacity and best friction reduction effect, followed by the elliptical morphology and the transverse ellipse arrangement. The denser the arrangement of the equal-width bars, the better the friction reduction effect was.

Optimization of Phage-Antibiotic Combinations against Staphylococcus aureus Biofilms.

Phage therapy has gained attention due to the spread of antibiotic-resistant bacteria and narrow pipeline of novel antibiotics. Phage cocktails are hypothesized to slow the overall development of resistance by challenging the bacteria with more than one phage. Here, we have used a combination of plate-, planktonic-, and biofilm-based screening assays to try to identify phage-antibiotic combinations that will eradicate preformed biofilms of Staphylococcus aureus strains that are otherwise difficult to kill. We have focused on methicillin-resistant S aureus (MRSA) strains and their daptomycin-nonsusceptible vancomycin-intermediate (DNS-VISA) derivatives to understand whether the phage-antibiotic interactions are altered by the changes associated with evolution from MRSA to DNS-VISA (which is known to occur in patients receiving antibiotic therapy). We evaluated the host range and cross-resistance patterns of five obligately lytic S. aureus myophages to select a three-phage cocktail. We screened these phages for their activity against 24-h bead biofilms and found that biofilms of two strains, D712 (DNS-VISA) and 8014 (MRSA), were the most resistant to killing by single phages. Specifically, even initial phage concentrations of 107 PFU per well could not prevent visible regrowth of bacteria from the treated biofilms. However, when we treated biofilms of the same two strains with phage-antibiotic combinations, we prevented bacterial regrowth when using up to 4 orders of magnitude less phage and antibiotic concentrations that were lower than our measured minimum biofilm inhibitory concentration. We did not see a consistent association between phage activity and the evolution of DNS-VISA genotypes in this small number of bacterial strains. IMPORTANCE The extracellular polymeric matrix of biofilms presents an impediment to antibiotic diffusion, facilitating the emergence of multidrug-resistant populations. While most phage cocktails are designed for the planktonic state of bacteria, it is important to take the biofilm mode of growth (the predominant mode of bacterial growth in nature) into consideration, as it is unclear how interactions between any specific phage and its bacterial hosts will depend on the physical properties of the growth environment. In addition, the extent of bacterial sensitivity to any given phage may vary from the planktonic to the biofilm state. Therefore, phage-containing treatments targeting biofilm infections such as catheters and prosthetic joint material may not be merely based on host range characteristics. Our results open avenues to new questions regarding phage-antibiotic treatment efficiency in the eradication of topologically structured biofilm settings and the extent of eradication efficacy relative to the single agents in biofilm populations.

Potential Lubricating Mechanism of Hyaluronic Acid for a Reduction of Albumin-Mediated Friction in the Artificial Joint System

The average lifespan of artificial joints is 15–25 years, but it is still too short for young and active patients. Human synovial albumin is easily adsorbed on the surfaces of artificial joint materials and has increased friction when subjected to conformational changes. Most studies have focused on the interaction between synovial fluid components and artificial joints when protein conformation has not been modified, but not on how to reduce friction and wear caused by denatured proteins. This study aimed to investigate whether hyaluronic acid could provide lubrication for albumin-mediated friction when high friction was caused by the disrupted secondary structure of albumin. Thermally processed human synovial albumin was used as denatured protein while friction testing, measurement of conformation, adsorption, and viscosity analysis were investigated. The results demonstrated that adding fresh hyaluronic acid to thermally processed albumin solution could reduce 50% of the friction coefficient caused by totally disrupted albumin. The viscosity of thermally processed albumin with fresh hyaluronic acid increased 40 times more than denatured albumin alone, and the adsorbed albumin area with fresh hyaluronic acid increased twice. The results showed hyaluronic acid provided lubrication by increasing the viscosity for friction mediated by denatured albumin, and it may provide a potential solution for prolonging the lifespan of artificial joints.

The use of PLA filled with fibrillar nanocellulose from wastepaper as an expansion joint material

The effect of nanocellulose (3 or 5 wt%) on the PLA properties was investigated. Moreover, the possibility of using such composites as an expansion joint material was considered. Nanocellulose was obtained from wastepaper by mechano-chemical treatment. The structure, impact strength, tensile strength of the composites and the adhesion to the cement were studied. It was observed that with the increasing nanocellulose content, the impact strength and tensile strength decreased because of weak interactions at the interface and formation of agglomerates.

Analysis of Low Temperature Anti-Cracking Property of Epoxy Materials for Cable Intermediate Joints

In this paper, multi-channel strain sensors are used to in-situ monitor the changes of strain with temperature under low temperatures for different stress angles in epoxy cladded metal inserts and the low temperature anti-cracking performances of the epoxy materials used for cable intermediate joint were analyzed. Compared with the foreign epoxy EP-0, the self-prepared toughed epoxy EP-1 has higher tensile strength, larger elongation at break and smaller modulus, showing a stronger toughness. The glass transition temperature of EP-0 and EP-1 epoxy materials are approximately the same. Besides, although the epoxy cladded metal inserts for EP-0 and EP-1 were both uncracked and intact when the temperature decreased from 0 to -70 °C, the strain and the stress at the stress angle R2 of EP-0 increased more rapidly with the decrease of the temperature than that of EP-1, which can be inferred that the cracking temperature of EP-0 is lower than that of EP-1. Thus, the low-temperature anti-cracking performance of self-made toughed epoxy material is better than that of commonly used foreign epoxy material.

Experimental Analysis of the Performance of Doweled Connections Reinforced with Glass-Fiber-Reinforced Polymer (GFRP) in Wood Pinus spp.

In line with technological advancements, the construction industry worldwide has sought more efficient building systems in relation to aspects such as increased productivity, reduced material waste and meeting the growing demand. The objective of this research was to use structural joints composed of composite dowels in laminated wood beams as an alternative to connect pieces of wood. Composite materials are composed of a matrix phase and a reinforcement phase and, in civil engineering, are generally applied as reinforcements in concrete structures. This article presents the structural performance of laminated pine timber with composite dowels made of fiber-reinforced polymeric resin (epoxy resin, hardener and glass fiber) (glass-fiber-reinforced polymer, GFRP) with a diameter of 12.5 mm, which was subjected to tensile force in the direction of the connection. For this, an experimental program was carried out that included characterization of the GFRP dowel, characterization of the woods used to make the connection and a tensile test of the connections with the dowels reinforced with fiberglass through a prototype designed specifically for the test. Subsequently, the results were compared with those observed in the literature. In the comparisons, it was possible to conclude that the joints with FRP pins exhibited better performance in terms of shear strength per section than those such as common nails, helical nails (Ardox) and composite structural pins (half-lap, 90°), which were 3.8 mm, 3.4 mm and 6 mm in diameter, respectively. This indicates that this composite material has potential for application in these types of connections. As an original contribution, it proves the feasibility of using this material in dowel joints for wooden structures.

Development and seismic performance evaluation of New high strength reinforced concrete column and steel beam (New-RCS) joint

Reinforced Concrete column and Steel beam (RCS) structural systems have recently become popular in Taiwan for office buildings. High seismic demand makes the size of conventional concrete columns enormous and the reinforcement over-crowded, which can be solved using high-strength materials. However, due to the lacuna of research regarding the usage of high-strength materials, existing design guidelines for the RCS systems have restricted the maximum grade of steel reinforcement to 410 MPa. Also, using high-strength materials in RCS joints necessitates innovative joint detailing and design to develop sufficient joint bearing and shear strength. Thus, a new high-strength reinforced concrete column and steel beam (New-RCS) joint was developed in this study, incorporating the use of Grade 690 MPa steel as reinforcement along with Grade 84 MPa concrete. A combination of wide flange bearing plate and flange doubler plate joint detailing was developed to improve the bearing and shear capacity of the joint. Also, a design methodology based on moment–curvature analysis was proposed to include the contribution of locked longitudinal reinforcement to bearing resistance. Subsequently, two large-scale interior beam-column subassemblies were subjected to quasi-static cyclic loading to verify the seismic behaviour of the proposed joint. One specimen was designed explicitly considering the material hardening and overstrength of steel beams. While the other was designed following the Taiwanese practice, which does not explicitly consider material hardening and overstrength but implicitly does it through strength reduction factors. Both the specimens exhibited a drift capacity of 4% with a stable and ductile hysteretic response and eventually failed through beam plastic hinging.

Synergy stabilization of vitamin E and D-sorbitol on crosslinked ultrahigh molecular weight polyethylene for artificial joint under in-vitro clinically relevant accelerated aging

Maintaining reliability remains a great challenge for ultrahigh molecular weight polyethylene (UHMWPE) bearings due to oxidation in biological environments. This work aimed at inspecting the efficacy of the hybrid antioxidant strategy in stabilizing crosslinked UHMWPE under an in vitro clinically relevant accelerated aging condition. The hybrid antioxidant system was composed of vitamin E (VE) and D-sorbitol (DS) as primary and secondary antioxidants, respectively. The already established in vitro clinically relevant accelerated aging was performed via squalene absorption and subsequent thermal oxidation treatment. Compared to the use of VE alone, the combination of VE and DS significantly protracted the oxidation induction time of UHMWPE with no apparent oxidation after aging, showing a notable synergistic effect on the oxidative stability of UHMWPE. The crosslink density was higher for VE/DS/UHMWPE than VE/UHMWPE at each aging period. It revealed that the hybrid antioxidant strategy settled the longstanding contradiction between oxidation stability and crosslinking of UHMWPE. Attributed to improved oxidation stability, there was a positive reversal in the tensile property between VE/DS/UHMWPE and VE/UHMWPE after aging, where comparable ultimate tensile strength and higher elongation at break were observed. These findings underline the high potential of the hybrid antioxidant strategy for developing artificial joint materials with desired ability to resist oxidation and balanced performance.

Experimental test and simulation calculation of fatigue properties of aluminum–titanium-steel explosive welded connector under tension-compression cyclic loading

The three-layer clad plate (aluminum alloy layer/commercial pure titanium layer/CCSB steel layer) was prepared by explosive welding as marine transition connector. The fatigue properties of clad plate were studied by experiment and finite element simulation. The fatigue limit and S–N curve were obtained by axial high-cycle fatigue test under tension-compression loading. The up-and-down method and group method were used respectively. Combining Static Structural module and DesignLife module based on the ANSYS Workbench Platform, the stress distribution, safety factor and fatigue life of clad plate under different loads were calculated. The results show that fatigue limit of Al–Ti-steel clad plate is 55 MPa, and the fatigue fracture mainly occurs in the 104∼106 cycles period in the stress range of 65 MPa∼100 MPa. The maximum relative error of fatigue life is 7.05%, and the relative error of fatigue limit is 0.45% between model and test fitting values. The results of finite element simulation have good agreement with the results of experimental method, which proves the feasibility and reliability of finite element simulation to analyze and forecast fatigue property of explosive welded clad plate. The position of the stress concentration is at the connection part between steel and pure titanium, while fatigue fracture occurs in the 3003 aluminum alloy layer because of the low tensile strength. Improving the tensile strength of Al-steel joint material is a key measure for solving the fracture problem of hull foundation.

Cascade Regulation of the Proliferation, Recruitment, and Differentiation of Stem Cells to Prevent Aseptic Loosening by GNPs/ECPP Particles Responding to Macrophages: In Vitro and In Vivo.

Modulating both inflammation and stem cells by designing an artificial joint material to obtain the continuous prevention and control on aseptic loosening (AL) is a novel strategy. In this paper, graphene/europium-doped calcium polyphosphate (GNPs/ECPP) particles were obtained by ultrasound method and spark plasma sintering (SPS) method. The prepared particles were used to modulate the inflammatory response and further obtain cascade regulation on the proliferation, recruitment, and differentiation of stem cells. The results showed that particles obtained by SPS had a stronger effect on promoting the proliferation and differentiation of stem cells, while by ultrasound method more stem cells were recruited. Besides, the graphene and Eu3+ contained in the particles obtained by SPS method could effectively play a synergistic role on the differentiation of stem cells. In vivo experiment results demonstrated that the composite particles effectively suppress the inflammatory response, recruit stem cells, and prevent AL by inhibiting the secretion of inflammatory factors.

Experiment and particle flow simulation of unloading induced shearing properties for jointed sandstone materials

Shear tests on sandstone containing non-connected joints under the unloading normal stress but fixed shear stress conditions were conducted with various initial normal stress and unloading rate. During the unloading process, continuous shear dilation could be observed. For initial normal stress = 5–20 MPa, the sliding initiation normal displacement decreased by 17.14–66.32 % but the sliding initiation shear displacement increased by 21.91–98.19 %. The sliding initiation normal stress declined by 7.18–15.57 % for unloading rate = 0.002–0.01 MPa/s but increased by a factor of 3.18–3.53 with the initial normal stress. Shear sliding of the jointed samples was more prone to occur at a smaller initial normal stress with a larger unloading rate. From the numerical simulation results via PFC2D, during the unloading process, cracking was first initiated from central part of the rock bridge and propagated gradually to coalesce with cracks developed from the joint tips. The penetrating fracture surfaces led to shear sliding of the jointed samples, and shear wear occurred on the fractures as shear displacement continued increasing. For unloading rate = 0.002–20 MPa/s, quantity of cracks corresponding to shear displacement of 1.2 mm decreased by 12.18–36.34 %. Cracking degree was more serious for the samples at a low unloading rate due to progressively developed cracks near the main failure planes before shear sliding and more accumulated cracks in the shearing wear stage for fractures under a larger normal stress.

Zwitterionic polyelectrolyte brush modified chitosan nanoparticles as functional biolubricant with good friction-reduction effect

Osteoarthritis (OA) caused by the articular cartilage degeneration is closely related to the lubrication dysfunction of joint. At present, injecting biolubricants into the joint cavity is regarded as an effective strategy for the treatment of arthritis. Herein, a biocompatible chitosan (CS)-based nanoparticles (NPs) biolubricant (CS-PMPC@DS NPs) with dual function of lubrication and anti-inflammatory was fabricated. Zwitterionic polyelectrolyte brush poly(2-methacryloyloxyethyl phosphorylcholine, PMPC) was grafted onto the NPs via atom transfer radical polymerization (ATRP) strategy, while the anti-inflammatory drug (diclofenac sodium, DS) was encapsulated within them. Under the synergistic effect rolling lubrication and hydration lubrication mechanisms, the obtained biolubricant exhibited superior lubrication performance in either artificial joint materials or cartilage contacts, which presents great potential for OA treatment.

Study on Stress Evolution and Crushing Behavior of Jointed Rock Mass under Confining Pressure and Joint Materials

To study the effects of confining pressure and joint material properties on stress evolution and fracture behavior of jointed rock mass under SHPB impact load, the numerical software LS-DYNA and the indoor SHPB impact system are used to carry out experimental research on intact rock mass and jointed rock mass. The peak stress, reflection and transmission coefficient, and specimen failure state of rock specimens under different schemes are obtained. The effects of confining pressure level and joint material properties on the propagation and attenuation law of explosive stress waves are expounded. The test results show that when the confining pressure is within a specific range, the impact resistance of the limestone specimen can be increased, and the more difficult it is to be destroyed. Moreover, if the confining pressure continues to increase after rising to the peak value, the impact resistance of rock specimens will decline. In that case, the impact resistance of the specimen will decrease—the dynamic strength of jointed rock mass changes with a change in joint material. The dynamic strength of cement jointed rock is the highest, that of gypsum jointed rock is the second, and that of epoxy resin jointed rock is the lowest. The impact damage resistance of the jointed rock has the same law as the above.

Evaluation of Physical Properties and Material Characterization for Structural Frame at the Stained Glass Windows to Gongju Jeil Church of the Registered Cultural Heritage in Korea

AbstractThe Christian Museum of Gongju Jeil Church was first built in 1931 and was largely damaged during the Korean War, but the walls and chimneys have been preserved. This building has a high architectural values in that the chapel was reconstructed in 1956, and maintains its original form through repair of damaged parts rather than new construction. The stained glass windows were as installed in 1979 and has a great significance in the Dalle de Verre method using lump glass. However, some of the stained glass damaged partially, such as various cracks and splits, and vertical and horizontal cracks in the joint fillers of supporting the colored glass. As the structural materials of the stained glass window, an iron frame and cement mortar filled with it were used, and corrosion of iron, cracking of mortar and granular decomposition appear partially due to weathering. In the joint fillers, the content of Ca and S is very high, indicating that gypsum were used as admixtures, and the gypsums grow in a rhombohedral and forms a bundle, which is investigated to have undergone recrystallization. As a result of modeling the ultrasonic velocity at the joint fillers, the left and right windows at the entrance show relatively weak in the range of 800 to 1,600m/s, and the lower right corner of the altar window and the upper left corner of the center window were also 1,000 to 1,800m/s, showing relatively low physical properties. And gypsums produced during the neutralization of lime mortar were detected in the joint fillers and contaminants on the surface. Such salts may cause damage to the joint material due to freezing and thawing, so appropriate preventive conservation is required. Also, since various damage types are complexly appearing in stained glass window and joint filler, customized conservation treatment should be reviewed through clinical tests.공주제일교회 기독교박물관은 1931년에 초축되었으며 한국전쟁으로 상당 부분 파손되었으나 벽체와 굴뚝 등이 보존되었다. 이 건물은 1956년 예배당을 재건하며 신축이 아닌 파손된 부분의 보수를 통해 원형을 유지하고 있다는 점에서 건축학적으로 높은 가치가 있다. 스테인드글라스는 1979년에 설치하였으며, 덩어리유리를 사용하는 달드베르(Dalle de Verre) 방식으로 큰 의미가 있다. 그러나 일부 스테인드글라스에서는 다양한 균열과 쪼개짐이 나타나고 색유리를 지지하는 줄눈에는 수직 및 수평균열이 확인되는 등 부분적인 손상을 입었다. 스테인드글라스의 구조재로는 철제 틀과 이를 충전한 시멘트 모르타르가 사용되었으며, 부분적으로 풍화작용에 따라 철제의 부식과 모르타르의 균열 및 입상분해가 나타난다. 줄눈재에서는 Ca과 S의 함량이 높아 석고를 혼화재로 사용하였음을 지시하며, 석고는 능형으로 성장하며 다발모양을 이루고 있는 것으로 보아 재결정작용을 거친 것으로 판단된다. 줄눈재의 초음파속도 모델링 결과, 입구 좌우창의 속도는 800~1,600㎧ 범위로 상대적으로 취약하며, 제단의 좌창 우측 하단과 중앙창 좌측 상단도 1,000~1,800㎧로 나타나 상대적으로 낮은 물성을 보였다. 또한 줄눈재와 표면오염물에서는 석회 모르타르의 중성화에서 생성되는 석고화합물이 검출되었다. 이와 같은 염류는 동결 및 융해작용에 따라 줄눈재의 손상을 일으킬 수 있어 적절한 예방보존이 필요하다. 스테인드글라스와 줄눈재에는 다양한 손상유형이 복합적으로 나타나고 있어 임상실험을 통해 맞춤형 보존처리를 검토해야 할 것이다.Keywords : stained glass window, joint filler, cement mortar, ultrasonic velocity, preventive conservation